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Configuration

Overview

Lighthouse CI configuration can be managed through a config file, environment variables, and CLI flag overrides.

Configuration File

Lighthouse CI will automatically look for a configuration file in the current working directory in the following priority order:

  1. .lighthouserc.js
  2. lighthouserc.js
  3. .lighthouserc.cjs
  4. lighthouserc.cjs
  5. .lighthouserc.json
  6. lighthouserc.json
  7. .lighthouserc.yml
  8. lighthouserc.yml
  9. .lighthouserc.yaml
  10. lighthouserc.yaml

Note that upward traversal is not supported. If you'd like to keep your lighthouse configuration in a different location, you can explicitly pass in a configuration file path to any lhci command using --config=./path/to/file.

Environment Variables

Any configuration option can also be set using environment variables prefixed with LHCI_, following the yargs API (so LHCI_PROPERTY_NAME__SUBPROPERTY_NAME is equivalent to --propertyName.subpropertyName).

LHCI_SERVER_BASE_URL=https://example.com lhci upload
# is equivalent to...
lhci upload --serverBaseUrl=https://example.com

CLI Flags

Of course CLI flags can set options as well in addition to nested properties!

lhci assert --preset=lighthouse:recommended --assertions.uses-webp-images=off

File Structure

The structure of the config file is segmented by command. Any options you see for a particular command can be set by the property of the same name in the config file.

lighthouserc.js:

module.exports = {
  ci: {
    collect: {
      // collect options here
    },
    assert: {
      // assert options here
    },
    upload: {
      // upload options here
    },
    server: {
      // server options here
    },
    wizard: {
      // wizard options here
    },
  },
};

lighthouserc.json:

{
  "ci": {
    "collect": {
      // collect options here
    },
    "assert": {
      // assert options here
    },
    "upload": {
      // upload options here
    },
    "server": {
      // server options here
    },
    "wizard": {
      // wizard options here
    }
  }
}

lighthouserc.yml:

ci:
  collect:
    # collect options here

  assert:
    # assert options here

  upload:
    # upload options here

  server:
    # server options here

  wizard:
    # wizard options here

Commands

Global Options

  --help             Show help                                         [boolean]
  --version          Show version number                               [boolean]
  --no-lighthouserc  Disables automatic usage of a .lighthouserc file. [boolean]
  --config           Path to JSON config file.

healthcheck

Runs diagnostics to ensure a valid configuration, useful when setting up Lighthouse CI for the first time to test your configuration.

Options:
  --fatal            Exit with a non-zero status code when a component fails the status check.
                                                                                           [boolean]
  --checks           The list of opt-in checks to include in the fatality check.             [array]

Examples

lhci healthcheck --fatal --checks=githubToken

autorun

Automatically run, with sensible defaults, lhci collect, lhci assert and lhci upload, depending on the options in your config. lhci autorun does not have many specific options for itself. Options for individual commands can be set by prefixing the option with the command name.

Note: in autorun all CLI flags for child commands must use the = syntax for atomic arguments. i.e. use lhci autorun --collect.numberOfRuns=5 and NOT lhci autorun --collect.numberOfRuns 5.

Examples

lhci autorun --collect.numberOfRuns=5
lhci autorun --upload.target=temporary-public-storage

failOnUploadFailure

Whether to consider failure to upload to the server a fatal error. By default, running upload through autorun only warns to avoid noisy failures from temporary connectivity loss.

Detecting collect.staticDistDir

Autorun will attempt to automatically detect the directory of your static site files. If you're using a popular framework like gatsby, create-react-app, etc, then you shouldn't need to take any action. lhci autorun will look for HTML files in the directories in the following order:

  • dist (default name for vue-cli, parcel, and webpack)
  • build (default name for create-react-app and preact-cli)
  • out (default name for Next.js, note this will only be generated with next export)
  • public (default name for gatsby)

If your productionized static assets live in a different folder, you'd like to run Lighthouse CI on a specific subset of your static pages, your project does not use a build step at all or a different server, see the lhci collect documentation for how to configure your project.

Detecting collect.startServerCommand

If no staticDistDir could be automatically detected, autorun will attempt to automatically detect the collect.startServerCommand based on our package.json. To allow autorun to automatically start your webserver, add an npm script named serve:lhci.

example package.json excerpt:

{
  "scripts": {
    "serve:lhci": "NODE_ENV=production npm run server"
  }
}

collect

Runs Lighthouse n times and stores the LHRs in a local .lighthouseci/ folder.

Options:
  --method                                              [string] [choices: "node"] [default: "node"]
  --headful                  Run with a headful Chrome                                     [boolean]
  --additive                 Skips clearing of previous collect data                       [boolean]
  --url                      A URL to run Lighthouse on. Use this flag multiple times to evaluate
                             multiple URLs.
  --staticDistDir            The build directory where your HTML files to run Lighthouse on are
                             located.
  --autodiscoverUrlBlocklist A URL to not include when autodiscovering urls from staticDistDir.
                             Use this flag multiple times to filter multiple URLs.
  --isSinglePageApplication  If the application is created by Single Page Application, enable
                             redirect to index.html.
  --chromePath               The path to the Chrome or Chromium executable to use for collection.
             [default: "/Applications/Google Chrome Canary.app/Contents/MacOS/Google Chrome Canary"]
  --puppeteerScript          The path to a script that manipulates the browser with puppeteer before
                             running Lighthouse, used for auth.
  --puppeteerLaunchOptions   The object of puppeteer launch options
  --psiApiKey                [psi only] The API key to use for PageSpeed Insights runner method.
                             You do not need to use this unless you wrote a custom version.
  --psiStrategy              [psi only] The strategy to use for PageSpeed Insights runner method. 
                              Use mobile or desktop. The default value is mobile
  --startServerCommand       The command to run to start the server.
  --startServerReadyPattern  String pattern to listen for started server.
                                                                  [string] [default: "listen|ready"]
  --startServerReadyTimeout  The number of milliseconds to wait for the server to start before
                             continuing                                    [number] [default: 10000]
  --settings                 The Lighthouse settings and flags to use when collecting
  --numberOfRuns, -n         The number of times to run Lighthouse.            [number] [default: 3]
  --maxAutodiscoverUrls      The maximum number of pages to collect when using the staticDistDir
                             option with no specified URL. Disable this limit by setting to 0.
                                                                               [number] [default: 5]
  --staticDirFileDiscoveryDepth The maximum depth of nested folders Lighthouse will look into to discover 
                                URLs on a static file folder.
                                                                               [number] [default: 2]

method

The method used to run Lighthouse. There are currently two options available, "node" which runs Lighthouse locally via node, and "psi" which runs Lighthouse by making a request to the PageSpeed Insights API.

The PageSpeed Insights method has the major limitation that only sites publicly available over the internet can be tested and no other collection options will be respected.

headful

Boolean that controls whether Chrome is launched in headless or headful mode. This flag does not apply when using puppeteerScript.

additive

Boolean that controls whether the .lighthouseci directory is cleared before starting. By default, this directory is cleared on every invocation of lhci collect to start fresh.

url

An array of the URLs that you'd like Lighthouse CI to collect results from.

When used with staticDistDir:

  • Automatic detection of URLs based on HTML files on disk will be disabled.
  • URLs will have their port replaced with the port of the local server that Lighthouse CI starts for you. This allows you to write URLs as http://localhost/my-static-page.html without worrying about the chosen temporary port.

When used without staticDistDir:

  • URLs will be used as-is without modification.

staticDistDir

The path to the directory where the project's productionized static assets are kept. Lighthouse CI uses this to spin up a static server on your behalf that will be used to load your site.

Use this option when the project is a static website to be hosted locally that does not require a separate server. DO NOT use this option if url will point to an origin that isn't localhost or the project uses startServerCommand to start a separate server.

isSinglePageApplication

Boolean that controls whether the static server started in staticDistDir should act like a single-page application that serves index.html instead of a 404 for unrecognized paths. This flag has no function when staticDistDir is not set.

chromePath

The path of the Chrome executable to use for puppeteerScript and running Lighthouse. Lighthouse CI will use Chrome installations in the following priority order:

  • chromePath option
  • CHROME_PATH Environment Variable
  • Executable path returned by puppeteer or puppeteer-core, if installed.
  • Highest priority installation returned by the chrome-launcher npm package.

puppeteerScript

An optional path to a JavaScript file that exports a function that uses puppeteer to login to your page, setup cache data, or otherwise manipulate the browser before Lighthouse is run.

NOTE: In order to use puppeteer scripts, you need to install puppeteer yourself, i.e. npm install --save puppeteer. Any version you like that has a .launch method compatible with v1.x or v2.x and works with the Chrome version installed in your environment should work.

When running Lighthouse CI on a page behind authentication, you'll need to authorize the browser that Lighthouse CI will be using. While there are several different options to accomplish this, the puppeteerScript option is one of the most flexible and convenient.

Here is the general flow when using puppeteer with LHCI:

|- puppeteer launches browser
|- LHCI runs the puppeteerScript
|- LHCI runs Lighthouse on URL A, run 1
|- LHCI runs Lighthouse on URL A, run 2
|- LHCI runs Lighthouse on URL A, run n
|- LHCI runs the puppeteerScript
|- LHCI runs Lighthouse on URL B, run 1
|- LHCI runs Lighthouse on URL B, run 2
...

Example puppeteer-script.js

/**
 * @param {puppeteer.Browser} browser
 * @param {{url: string, options: LHCI.CollectCommand.Options}} context
 */
module.exports = async (browser, context) => {
  // launch browser for LHCI
  const page = await browser.newPage();
  await page.goto('http://localhost:8080/login');
  await page.type('#username', 'admin');
  await page.type('#password', 'password');
  await page.click('[type="submit"]');
  await page.waitForNavigation();
  // close session for next run
  await page.close();
};

Lighthouse CI will then use the browser that this script sets up when running Lighthouse. Keep in mind the browser is kept open across all URLs, so if you're keeping auth in cookies then everything should be remembered between runs. If you store your credentials in localStorage or anything other than a cookie you might want to pair this option with --settings.disableStorageReset to force Lighthouse to keep the cache state.

For more information on how to use puppeteer, read up on their API docs.

puppeteerLaunchOptions

An object of options to pass to puppeteer's launch method. Only used when puppeteerScript is set.

psiApiKey

method=psi only

The API key to use for making PageSpeed Insights requests. Required if using method=psi. You can obtain a PSI API key from Google APIs.

psiApiEndpoint

method=psi only

The API endpoint to hit for making a PageSpeed Insights request. It is very unlikely you should need to use this option. Only use this if you have self-hosted a custom version of the PSI API.

psiStrategy

method=psi only

Use this option to change the strategy to use for PageSpeed Insights runner method. Use mobile or desktop. The default value is mobile.

startServerCommand

The shell command to use to start the project's webserver. LHCI will use this command to start the server before loading the urls and automatically shut it down once collection is complete.

Use this option when your project requires a special webserver. DO NOT use this option when your project is just a collection of static assets. Use staticDistDir instead to use the built-in static server.

startServerReadyPattern

The regex pattern to look for in the server command's output before considering the server ready for requests. Only used when startServerCommand is set.

For example, when using the default listen|ready, Lighthouse would start collecting results once the the startServerCommand process printed Listening on port 1337 to stdout.

startServerReadyTimeout

The maximum amount of time in milliseconds to wait for startServerCommand to print the startServerReadyPattern before continuing anyway. Only used when startServerCommand is set.

settings

The Lighthouse CLI flags to pass along to Lighthouse. This can be used to change configuration of Lighthouse itself. See Lighthouse documentation on custom configs for more.

Note that the following options cannot be used because LHCI uses them internally:

  • port
  • auditMode
  • gatherMode
  • output
  • outputPath
  • channel
  • cli-flags-path

Example:

{
  "ci": {
    "collect": {
      "settings": {
        // Don't run certain audits
        "skipAudits": ["redirects-http"],
        // Don't clear localStorage/IndexedDB/etc before loading the page.
        "disableStorageReset": true,
        // Wait up to 90s for the page to load
        "maxWaitForLoad": 90000,
        // Use applied throttling instead of simulated throttling
        "throttlingMethod": "devtools",
        // Use a custom Lighthouse config file.
        "configPath": "path/to/custom/config.js"
      }
    }
  }
}

numberOfRuns

The number of times to collect Lighthouse results on each url. This option helps mitigate fluctations due to natural page variability.

Examples

# Basic usage
lhci collect --numberOfRuns=5 --url=https://example.com
# Have LHCI start a server before running
lhci collect --start-server-command="yarn serve" --url=http://localhost:8080/
# Have LHCI use the built-in server on a static directory
lhci collect --staticDistDir=./dist
# Have LHCI use the built-in server and audit a specific URL
lhci collect --staticDistDir=./public --url=http://localhost/products/pricing/
# Run on multiple URLs
lhci collect --url=https://example-1.com --url=https://example-2.com
# Have LHCI start a server and login with puppeteer before running
lhci collect --start-server-command="yarn serve" --url=http://localhost:8080/ --puppeteer-script=./path/to/login-with-puppeteer.js

staticDirFileDiscoveryDepth

The maximum depth level of nested folders that Lighthouse will look into to discover URLs. If not set, this will default to 2.

Example


public/
├── index.html               #level 0                      
├── contact/
│   └── index.html           #level 1
├── projects/
│   ├──index.html            #level 1
│   └── crisis/
│       ├──index.html        #level 2
│       └── earthquake/
│           └── index.html   #level 3

upload

Saves the runs in the .lighthouseci/ folder to desired target and sets a GitHub status check when the GitHub token is available and target is not filesystem.

Options:
  --target                       The type of target to upload the data to. If set to anything other
                                 than "lhci", some of the options will not apply.
              [string] [choices: "lhci", "temporary-public-storage", "filesystem"] [default: "lhci"]
  --token                        [lhci only] The Lighthouse CI build token for the project.[string]
  --ignoreDuplicateBuildFailure  [lhci only] Whether to ignore failures (still exit with code 0)
                                 caused by uploads of a duplicate build.                   [boolean]
  --githubToken                  The GitHub token to use to apply a status check.           [string]
  --githubApiHost                The GitHub host to use for the status check API request. Modify
                                 this when using on a GitHub Enterprise server.
                                                        [string] [default: "https://api.github.com"]
  --githubAppToken               The LHCI GitHub App token to use to apply a status check.  [string]
  --githubStatusContextSuffix    The suffix of the GitHub status check context label.       [string]
  --extraHeaders                 [lhci only] Extra headers to use when making API requests to the
                                 LHCI server.
  --basicAuth.username           [lhci only] The username to use on a server protected with HTTP
                                 Basic Authentication.                                      [string]
  --basicAuth.password           [lhci only] The password to use on a server protected with HTTP
                                 Basic Authentication.                                      [string]
  --serverBaseUrl                [lhci only] The base URL of the LHCI server where results will be
                                 saved.                          [default: "http://localhost:9001/"]
  --uploadUrlMap                 [temporary-public-storage only] Whether to post links to historical
                                 base results to storage or not. Defaults to true only on master
                                 branch.                                  [boolean] [default: false]
  --urlReplacementPatterns       [lhci only] sed-like replacement patterns to mask non-deterministic
                                 URL substrings.                                   [array] [default:
  ["s#:[0-9]{3,5}/#:PORT/#","s/[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}/UUID/ig"
                                                                                                  ]]
  --outputDir                    [filesystem only] The directory in which to dump Lighthouse results.                                           [string]
  --reportFilenamePattern        [filesystem only] The pattern to use for naming Lighthouse reports.
                                                                       [string] [default:
  "%%HOSTNAME%%-%%PATHNAME%%-%%DATETIME%%.report.%%EXTENSION%%"]

target

The target location to which Lighthouse CI should upload the reports.

When to use target=temporary-public-storage:

  • You want to setup Lighthouse CI as quickly as possible without any costs.
  • You're OK with your reports being available to anyone on the internet with the link.
  • You're OK with your reports being automatically deleted after a few days.
  • You're OK with your reports being stored on GCP Cloud Storage.
  • You've read and agreed to the full terms of service and privacy policy of the service.

When to use target=lhci:

  • You want to store Lighthouse reports for longer than a few days.
  • You want to control access to your Lighthouse reports.
  • You've setup a Lighthouse CI server.

When to use target=filesystem:

  • You want to process the raw Lighthouse results yourself locally.
  • You want access to the report files on the local filesystem.
  • You don't want to upload the results to a custom location that isn't supported by Lighthouse CI.
  • You don't need detailed status checks in GitHub

token

target=lhci only

The build token for your Lighthouse CI project. Required when using target=lhci. This token should be given to you by lhci wizard --wizard=new-project. If you've forgotten your token, connect directly to your server and run lhci wizard --wizard=reset-build-token.

ignoreDuplicateBuildFailure

target=lhci only

Boolean that controls whether upload failures due to duplicate build hashes should be ignored. The build token only allows the creation of data on the server and not the editing or destruction of data on the LHCI server. When the CLI attempts to upload a Lighthouse report for a hash that already exists, the server will reject it.

Use this option when you don't run Lighthouse CI as the last step of your CI process or reruns are common.

githubToken

The GitHub token to use when setting a status check on a GitHub PR. Use this when the project is hosted on GitHub and not using the official GitHub App.

githubApiHost

The GitHub API host to use when attempting to set a status check. Use this when the project is hosted on a private GitHub enterprise server and not using the public GitHub API.

githubAppToken

The GitHub App token returned when installing the GitHub App. Use this to set status checks on GitHub PRs when using the official GitHub App.

githubStatusContextSuffix

The suffix to use when setting the status check on a GitHub PR.

For example, by default lhci is used as the root of the status check label, but this can be configured to lhci-app by setting githubStatusContextSuffix to -app.

extraHeaders

target=lhci only

A map of additional headers to add the requests made to the LHCI server. Useful for adding bespoke auth tokens.

basicAuth

target=lhci only

An object containing a username and password pair for authenticating with a Basic auth protected LHCI server. Use this setting when you've protected your LHCI server with Basic auth.

Example:

{
  "ci": {
    "upload": {
      "basicAuth": {
        "username": "myAdminUser",
        "password": "LighthouseRocks!"
      }
    }
  }
}

serverBaseUrl

target=lhci only

The base URL of the LHCI server to upload to. Required when using target=lhci.

uploadUrlMap

target=temporary-public-storage only

Boolean that controls whether to update the latest build in temporary public storage associated with this repo. If you use master as your default branch, DO NOT use this option. If you don't use master as your default branch, set this option when you upload results from your actual default branch.

urlReplacementPatterns

target=lhci only

A list of replacement patterns that will mask differences in tested URLs that you wish to hide for display or treat as the same. The urlReplacementPatterns are used to identify the same URLs for diff comparisons and as preprocessing for GitHub status check labels.

For example, by default Lighthouse CI will automatically replace the port of tested URLs. A localhost static server port may change on each additional invocation, but with urlReplacementPatterns the port number is replaced with PORT so all builds

Format: s{DELIMITER}{SEARCH_REGEX}{DELIMITER}{REPLACEMENT}{DELIMITER}{SEARCH_REGEX_FLAGS}

Notes:

  • There is no escape support for the delimiter, so you must choose a delimiter character that does not appear in your search regex or your replacement.
  • Beware of double-escaping requirements. If you're passing a string in JS or an argument through a shell, you may need to use \\ in order for a \ to be seen by Lighthouse CI.
  • If you set urlReplacementPatterns yourself, you will lose the defaults provided by Lighthouse CI. If you need the functionality provided by the defaults, be sure to copy them into your configuration as well.
  • You can quickly experiment with various replacement patterns using this online REPL.

Examples:

  • s/Foo/Bar/g - Replace all occurrences of Foo with Bar, case-sensitive.
  • s/v\d+/VERSION/i - Replace the first sequence of a v followed by digits with VERSION, case-insensitive.
  • s#(//.*?)/.*$#$1/replaceThePath# - Replace the entire URL following the origin with /replaceThePath using # as the delimiter character and a group reference.

outputDir

target=filesystem only

The directory relative to the current working directory in which to output a manifest.json along with the Lighthouse reports collected. Any existing manifest.json in that directory will be overwritten.

Sample file structure for --outputDir=./lhci on https://www.example.com/page

|- (cwd)
  |- lhci
    |- manifest.json
    |- www_example_com-_page-2020_05_22_21_15_05.report.json
    |- www_example_com-_page-2020_05_22_21_15_05.report.html

The manifest.json has the following structure.

[
  {
    "url": "https://www.example.com/page",
    "isRepresentativeRun": true, // whether it's the median run
    "htmlPath": "/path/to/cwd/lhci/www_example_com-_page-2020_05_22_21_15_05.report.html",
    "jsonPath": "/path/to/cwd/lhci/www_example_com-_page-2020_05_22_21_15_05.report.json",
    "summary": {"performance": 0.95, "seo": 0.9, "best-practices": 1}
  }
]

reportFilenamePattern

target=filesystem only

The pattern to use for report filenames when writing the reports to the filesystem. Basic string interpolation is supported replacing %%HOSTNAME%% with the URL's hostname, %%PATHNAME%% with the page path, %%DATETIME%% with the ISO string of the UTC report generated timestamp, %%DATE%% with the ISO-style string of the UTC report generated date, %%EXTENSION%% with the extension of the file.

In the case of filename collisions between runs, the last written report wins and all others will be overwritten. Median reports are written to disk last.

Build Context

When uploading to the Lighthouse CI server, the CLI will attempt to automatically infer the build context such as git hash, author, message, ancestor, etc. In most cases, there's nothing you need to change about this, but if you're running without a git repo, in a Jenkins environment, a CI provider we haven't documented yet, or are just running into errors, you can control the build context yourself.

The following environment variables override the inferred build context settings.

Name Example Format
LHCI_BUILD_CONTEXT__GIT_REMOTE git@github.com:GoogleChrome/lighthouse-ci.git
LHCI_BUILD_CONTEXT__GITHUB_REPO_SLUG GoogleChrome/lighthouse-ci
LHCI_BUILD_CONTEXT__CURRENT_HASH e7f1b0fa3aebb6ef95e44c0d0b820433ffdd2e63
LHCI_BUILD_CONTEXT__ANCESTOR_HASH 78bafdcaf40e204c0d0b81b90bb76b9aa5834e11
LHCI_BUILD_CONTEXT__COMMIT_TIME 2019-11-29T16:43:39-05:00
LHCI_BUILD_CONTEXT__CURRENT_BRANCH dev_branch_1234
LHCI_BUILD_CONTEXT__COMMIT_MESSAGE Daily run of Lighthouse
LHCI_BUILD_CONTEXT__AUTHOR Patrick Hulce <patrick.hulce@example.com>
LHCI_BUILD_CONTEXT__AVATAR_URL https://example.com/patrickhulce.jpg
LHCI_BUILD_CONTEXT__EXTERNAL_BUILD_URL https://my-jenkins.example.com/jobs/123

Examples

lhci upload --config=./lighthouserc.json
lhci upload --target=temporary-public-storage
lhci upload --serverBaseUrl=http://lhci.my-custom-domain.com/
lhci upload --extraHeaders.Authorization='Bearer X92sEo3n1J1F0k1E9'
lhci upload --basicAuth.username="customuser" --basicAuth.password="LighthouseRocks"
lhci upload --githubToken="$MY_ENTERPRISE_GITHUB_TOKEN" --githubApiHost="https://custom-github-server.example.com/api/v3"

assert

Asserts the conditions in the Lighthouse CI config and exits with the appropriate status code if there were any failures.

Options:
  --preset                   The assertions preset to extend
                          [choices: "lighthouse:all", "lighthouse:recommended", "lighthouse:no-pwa"]
  --assertions               The assertions to use.
  --budgetsFile              The path (relative to cwd) to a budgets.json file.
  --includePassedAssertions  Whether to include the results of passed assertions in the output.
                                                                                           [boolean]

assertions

The result of any audit in Lighthouse can be asserted. Assertions are keyed by the Lighthouse audit ID and follow an eslint-style format of level | [level, options]. For a reference of the audit IDs in each category, you can take a look at the default Lighthouse config. When no options are set, the default options of {"aggregationMethod": "optimistic", "minScore": 1} are used.

{
  "ci": {
    "assert": {
      "assertions": {
        "first-contentful-paint": "off",
        "installable-manifest": ["warn", {"minScore": 1}],
        "uses-responsive-images": ["error", {"maxLength": 0}]
      }
    }
  }
}
Categories

The score of any category in Lighthouse can also be asserted. Assertions are keyed by categories:<categoryId> and follow the same eslint-style format as audit assertions. Note that this just affects the category score and will not affect any assertions on individual audits within the category.

{
  "ci": {
    "assert": {
      "assertions": {
        "categories:performance": ["warn", {"minScore": 0.9}],
        "categories:accessibility": ["error", {"minScore": 1}]
      }
    }
  }
}
Levels

There are three Lighthouse CI assertion levels.

  • off - The audit result will not be checked. If an audit is not found in the assertions object, it is assumed to be off.
  • warn - The audit result will be checked, and the result will be printed to stderr, but failure will not result in a non-zero exit code.
  • error - The audit result will be checked, the result will be printed to stderr, and failure will result in a non-zero exit code.
Properties

The score, details.items.length, and numericValue properties of audit results can all be checked against configurable thresholds. Use minScore, maxLength, and maxNumericValue properties, respectively, in the options object to control the assertion.

{
  "ci": {
    "assert": {
      "assertions": {
        "audit-id-1": ["warn", {"maxNumericValue": 4000}],
        "audit-id-2": ["error", {"minScore": 0.8}],
        "audit-id-3": ["warn", {"maxLength": 0}]
      }
    }
  }
}
Aggregation Methods

When checking the results of multiple Lighthouse runs, there are multiple strategies for aggregating the results before asserting the threshold.

  • median - Use the median value from all runs.
  • optimistic - Use the value that is most likely to pass from all runs.
  • pessimistic - Use the value that is least likely to pass from all runs.
  • median-run Use the value of the run that was determined to be "most representative" of all runs based on key performance metrics. Note that this differs from median because the audit you're asserting might not be the performance metric that was used to select the median-run.
User Timings

Your custom user timings using performance.mark and performance.measure can be asserted against as well.

The general format for asserting against a user timing value is "user-timings:<kebab-cased-name>": ["<level>", {maxNumericValue: <value in milliseconds>}]. For example, if you wanted to assert that a mark with name My Custom Mark started within the first 2s of page load and that a measure my:custom-@-Measure lasted fewer than 50 ms you would use the following assertions config.

Note that only the first matching entry with the name will be used from each run and the rest will be ignored.

{
  "ci": {
    "assert": {
      "assertions": {
        "user-timings:my-custom-mark": ["warn", {"maxNumericValue": 2000}],
        "user-timings:my-custom-measure": ["error", {"maxNumericValue": 50}]
      }
    }
  }
}

assertMatrix

assertMatrix can be used to assert against multiple URLs at the same time. When checking the results of runs against multiple URLs, different assertions can be made for different URL patterns.

The below example warns when FCP is above 2 seconds on all pages and warns when TTI is above 5 seconds on all secure pages whose path starts with /app. Assertion matrix configurations can be used to differentiate production from development, landing pages from single-page apps, and more.

{
  "ci": {
    "assert": {
      "assertMatrix": [
        {
          "matchingUrlPattern": ".*",
          "assertions": {
            "first-contentful-paint": ["warn", {"maxNumericValue": 2000}]
          }
        },
        {
          "matchingUrlPattern": "https://[^/]+/app",
          "assertions": {
            "interactive": ["warn", {"maxNumericValue": 5000}]
          }
        }
      ]
    }
  }
}

preset

There are three presets available to provide a good starting point. Presets can be extended with manual assertions.

  • lighthouse:all - Asserts that every audit received a perfect score. This is extremely difficult to do. Only use as a base on very high quality, greenfield projects and lower the tresholds as needed.
  • lighthouse:recommended - Asserts that every audit outside performance received a perfect score, that no resources were flagged for performance opportunities, and warns when metric values drop below a score of 90. This is a more realistic base that disables hard failures for flaky audits.
  • lighthouse:no-pwa - lighthouse:recommended but without any of the PWA audits enabled.

The below example uses the lighthouse:no-pwa preset but disables a few audits we're not quite ready to pass yet and increases the limit on an audit with a numericValue.

{
  "ci": {
    "assert": {
      "preset": "lighthouse:no-pwa",
      "assertions": {
        "dom-size": ["error", {"maxNumericValue": 3000}],
        "offscreen-images": "off",
        "color-contrast": "off",
        "tap-targets": "off"
      }
    }
  }
}

budgetsFile

Instead of configuring using Lighthouse CI assertions against Lighthouse audits, a budget.json file can be used instead. This option cannot be used in conjunction with any other assert option.

{
  "ci": {
    "assert": {
      "budgetsFile": "path/from/cwd/to/budget.json"
    }
  }
}

If you'd like to consolidate multiple assertion configuration files and avoid multiple calls to lhci assert, you can also configure your budgets alongside your other Lighthouse CI assertions instead. Budget assertions follow the form resource-summary:<resourceType>:(size|count).

Note: when using the Lighthouse CI style assertions the maxNumericValue unit for file size is in bytes while the budget.json unit for file size is in kilobytes.

{
  "ci": {
    "assert": {
      "assertions": {
        "first-contentful-paint": ["warn", {"maxNumericValue": 4000}],
        "viewport": "error",
        "resource-summary:document:size": ["error", {"maxNumericValue": 14000}],
        "resource-summary:font:count": ["warn", {"maxNumericValue": 1}],
        "resource-summary:third-party:count": ["warn", {"maxNumericValue": 5}]
      }
    }
  }
}

includePassedAssertions

Boolean that controls whether passed assertions should be included in the output. Only assertions that didn't pass are shown normally.

Examples

lhci assert --config=./lighthouserc.json
lhci assert --budgetsFile=./budgets.json
lhci assert --preset=lighthouse:recommended --assertions.speed-index=off
lhci assert --preset=lighthouse:recommended --includePassedAssertions

open

Open a local lighthouse report that has been created using collect. There is no configuration for this command.

lhci open

wizard

Runs an interactive step-by-step wizard to accomplish various Lighthouse CI tasks. Resetting tokens will require a server configuration file and running on a device that has direct write access to the server's database.

lhci wizard
? Which wizard do you want to run? (Use arrow keys)
❯ new-project
  reset-build-token
  reset-admin-token

server

Starts the LHCI server. This command is unique in that it is likely run on infrastructure rather than in your build process. Learn more about the LHCI server and how to setup your personal LHCI server accessible over the internet.

Run Lighthouse CI server

Options:
  --logLevel                                               [string] [choices: "silent", "verbose"] [default: "verbose"]
  --port, -p                                                                                   [number] [default: 9001]
  --storage.storageMethod                                                    [string] [choices: "sql"] [default: "sql"]
  --storage.sqlDialect                            [string] [choices: "sqlite", "postgres", "mysql"] [default: "sqlite"]
  --storage.sqlDatabasePath               The path to a SQLite database on disk.
  --storage.sqlConnectionUrl              The connection url to a postgres or mysql database.
  --storage.sqlConnectionSsl              Whether the SQL connection should force use of SSL [boolean] [default: false]
  --storage.sqlDangerouslyResetDatabase   Whether to force the database to the required schema. WARNING: THIS WILL
                                          DELETE ALL DATA                                    [boolean] [default: false]
  --storage.sqlMigrationOptions.tableName Use a different Sequelize table name.                                [string]
  --basicAuth.username                    The username to protect the server with HTTP Basic Authentication.   [string]
  --basicAuth.password                    The password to protect the server with HTTP Basic Authentication.   [string]

port

The port for the server to listen on. A value of 0 will use a random available port. https://nodejs.org/api/net.html#net_server_listen_port_host_backlog_callback

host

The host to bind the server to. The default is to use the unspecified IPv6 address (::) when IPv6 is available, or the unspecified IPv4 address (0.0.0.0) otherwise. To only accept connections on IPv4 use 0.0.0.0 as host.

storage

Options that control how the historical Lighthouse data is stored. Currently only SQL-based storage mechanisms are supported.

storage.sqlDialect

One of mysql, postgres, or sqlite. sqlite in a local file on disk has been sufficient for most use cases.

storage.sqlDatabasePath

sqlDialect=sqlite only

The path to the sqlite database on the local filesystem relative to the current working directory.

storage.sqlConnectionUrl

sqlDialect=mysql or sqlDialect=postgres only

The database connection URL string for the MySQL or PostgreSQL database of the form <dialect>://<user>:<password>@<host>:<port>/<database>.

storage.sqlDangerouslyResetDatabase

WARNING: this option will delete all data in the database

Boolean flag useful during setup if things have gone wrong. This flag will reset the schema of all LHCI tables to factory fresh, deleting all data in the process.

storage.sequelizeOptions

Additional raw options object to pass to sequelize. Refer to the sequelize documentation for more information on available settings.

storage.sqlMigrationOptions.tableName

Use a different Sequelize table name. Default: SequelizeMeta. Refer to the sequelize migrations documentation for more information.

psiCollectCron

The configuration to automatically collect results using the PageSpeed Insights API.

psiCollectCron.psiApiKey

The API key to use with the PSI API. You can obtain a PSI API Key by following the official documentation.

psiCollectCron.sites

The array of sites to collect results for. This configuration will only be possible once the server has been setup and project have been created.

psiCollectCron.sites[i].urls

The array of URLs on which to run Lighthouse. These URLs must be publicly accessible to anyone on the internet in order for PSI to be able to run.

psiCollectCron.sites[i].schedule

The cron-style schedule on which to collect results.

Examples

Every 10 minutes, 24/7 - */10 * * * *

Daily at midnight - 0 0 * * *

Monday-Friday at 11:30 AM - 30 11 * * 1-5

psiCollectCron.sites[i].projectSlug

The unique slug identifer of the project in which results should be saved. The easiest way to tell the project slug is to open the project on the server and look at the URL bar. The project slug for the URL below is debugger-protocol-viewer.

image

You can also list projects from the API to find the projectSlug.

curl http://localhost:9001/v1/projects | jq '.[] |.name,.slug'
psiCollectCron.sites[i].numberOfRuns

Optional The number of reports to collect for each URL on each iteration of the schedule. Defaults to 5.

psiCollectCron.sites[i].label

Optional The human friendly label for this set of URLs to use when logging status to stdout/stderr. Not used for anything other than logging.

psiCollectCron.sites[i].branch

Optional The "branch" on which to report the results. Defaults to the base branch of the project referenced by projectSlug.

psiCollectCron.sites[i].maxNumberOfParallelUrls

Optional The maximum number of requests to send to the PageSpeed Insights API concurrently. Defaults to Infinity (all urls sent in parallel).

psiCollectCron.sites[i].categories

Optional An array containing the categories to test for each url in this site. Defaults to ['performance', 'accessibility', 'best-practices', 'seo'] (all categories).

psiCollectCron.sites[i].strategy

Optional The strategy that the PageSpeed Insights API should use when testing each url in this site. Can be either desktop or mobile. Defaults to mobile.

deleteOldBuildsCron

The configuration to automatically delete old records. This job only works when storage.storageMethod is set sql. Might be an array of objects, or just a single object.

deleteOldBuildsCron[i].schedule

The cron-style schedule on which to collect results.

deleteOldBuildsCron[i].maxAgeInDays

A number of days to keep a records.

deleteOldBuildsCron[i].onlyBranches

Array of branch names, which should be deleted

deleteOldBuildsCron[i].skipBranches

Array of branch names, which should be excluded during cleanup

basicAuth

basicAuth.username
basicAuth.password

Protects the server from casual snooping by using single-user HTTP Basic auth. When enabled, all requests to the server UI and API will require HTTP Basic authentication with the specified credentials.

Read more about protecting the server in the server security documentation.

Examples

Many server examples require more advanced configuration than the CLI flags allow. See the common examples section for more complete usage examples using a config file.

lhci server --storage.sqlDatabasePath=./lhci.db
lhci server --storage.sqlDialect=postgres --storage.sqlConnectionUrl="postgres://user@localhost/lighthouse_ci_db"
lhci server --storage.sqlDatabasePath=./lhci.db --basicAuth.username="customuser" --basicAuth.password="LighthouseRocks"

Recommended Configurations

Easy Mode

Recommended for those new to Lighthouse.

If you're just beginning to measure your project with Lighthouse, start slowly and manually monitor your scores first by only configuring upload. Once you're comfortable, consider moving up to Intermediate.

Combine this with GitHub App to get convenient links to your reports.

{
  "ci": {
    "upload": {
      "target": "temporary-public-storage"
    }
  }
}

Next Level

Recommended for those familiar with Lighthouse, but new to performance measurement in CI.

If you're used to running Lighthouse on your project but still have some work to do, assert the recommended preset but disable the audits you're currently failing. Consider setting up the Lighthouse CI server to track your scores over time.

{
  "ci": {
    "assert": {
      "preset": "lighthouse:recommended",
      "assertions": {
        "offscreen-images": "off",
        "uses-webp-images": "off",
        "color-contrast": "off"
        // ...
      }
    },
    "upload": {
      "target": "temporary-public-storage"
    }
  }
}

The Complete Experience

Recommended for seasoned Lighthouse users who are used to measuring performance in CI.

If you're a Lighthouse pro, assert the recommended preset, increase the number of runs, and set budgets for your performance metrics. Set up the Lighthouse CI server to track your scores over time and receive build diffs when your metrics regress.

{
  "ci": {
    "collect": {
      "numberOfRuns": 5
    },
    "assert": {
      "preset": "lighthouse:recommended",
      "assertions": {
        "first-contentful-paint": [
          "error",
          {"maxNumericValue": 2000, "aggregationMethod": "optimistic"}
        ],
        "interactive": ["error", {"maxNumericValue": 5000, "aggregationMethod": "optimistic"}]
        // ...
      }
    },
    "upload": {
      "target": "lhci",
      "serverBaseUrl": "https://lhci.example.com"
    }
  }
}

Common Examples

Custom build directory

{
  "ci": {
    "collect": {
      "staticDistDir": "./_site"
    }
  }
}

Custom Lighthouse Config

{
  "ci": {
    "collect": {
      "settings": {
        "configPath": "./path/to/lighthouse/config.js",
        "plugins": ["lighthouse-plugin-field-performance"],
        "disableStorageReset": true
      }
    }
  }
}

Desktop emulation

{
  "ci": {
    "collect": {
      "settings": {
        "preset": "desktop"
      }
    }
  }
}

Custom Chrome Flags

{
  "ci": {
    "collect": {
      "settings": {
        "chromeFlags": "--disable-gpu --no-sandbox"
      }
    }
  }
}

Page Behind Authentication

{
  "ci": {
    "collect": {
      "settings": {
        "extraHeaders": "{\"Cookie\": \"token=1234\"}"
      }
    }
  }
}
module.exports = {
  ci: {
    collect: {
      settings: {
        extraHeaders: JSON.stringify({Cookie: 'token=1234'}),
      },
    },
  },
};

Non-NodeJS Development Server

{
  "ci": {
    "collect": {
      "startServerCommand": "rails server -e production",
      "url": [
        "http://localhost:3000/",
        "http://localhost:3000/pricing",
        "http://localhost:3000/support"
      ]
    }
  }
}

Budgets.json

{
  "ci": {
    "collect": {
      "settings": {
        // This setting makes the budgets section appear in the Lighthouse report itself
        "budgetPath": "./path/to/budgets.json"
      }
    },
    "assert": {
      "assertions": {
        // This setting asserts that the budgets audit passed in Lighthouse CI
        "performance-budget": "error"
      }
    }
  }
}

Basic Auth (Client)

{
  "ci": {
    "upload": {
      "basicAuth": {
        "username": "myusername",
        "password": "LighthouseRocks"
      }
    }
  }
}

Basic Auth (Server)

{
  "ci": {
    "server": {
      "basicAuth": {
        "username": "myusername",
        "password": "LighthouseRocks"
      },
      "storage": {
        // ...
      }
    }
  }
}

Socket Path for Database Connection

{
  "ci": {
    "server": {
      "storage": {
        "sqlDialect": "mysql",
        "sqlDialectOptions": {
          "socketPath": "/var/lib/mysql/mysql.sock"
        },
        "sequelizeOptions": {
          "database": "reports",
          "username": "admin",
          "password": "password"
        }
      }
    }
  }
}

Custom SSL Certificate for Database Connection

const fs = require('fs');

module.exports = {
  ci: {
    server: {
      storage: {
        storageMethod: 'sql',
        sqlDialect: 'postgres',
        sqlConnectionSsl: true,
        sqlConnectionUrl: process.env.DATABASE_URL,
        sqlDialectOptions: {
          ssl: {
            ca: fs.readFileSync('./certs/ca.crt', 'utf8'),
            key: fs.readFileSync('./certs/client.foo.key', 'utf8'),
            cert: fs.readFileSync('./certs/client.foo.crt', 'utf8'),
          },
        },
      },
    },
  },
};

Custom Sequelize Configuration

See the sequelize docs for more information on available settings.

module.exports = {
  ci: {
    server: {
      storage: {
        storageMethod: 'sql',
        sqlDialect: 'postgres',
        sqlConnectionSsl: true,
        sqlConnectionUrl: process.env.DATABASE_URL,
        sqlDialectOptions: {
          // this flag also needs to be set in order to make a secure connection if not setting custom certificates
          ssl: true,
        },
        sequelizeOptions: {
          pool: {
            acquire: 30000,
          },
        },
      },
    },
  },
};

Server Cron Job to Monitor Production URLs via PSI

module.exports = {
  ci: {
    server: {
      psiCollectCron: {
        psiApiKey: process.env.PSI_API_KEY,
        sites: [
          {
            label: 'Production',
            projectSlug: 'the-project',
            schedule: '0 * * * *', // at the top of the hour, every hour
            numberOfRuns: 5,
            urls: ['http://example.com', 'http://example.com/pricing'],
          },
          {
            label: 'Development',
            branch: 'dev',
            projectSlug: 'the-project',
            schedule: '*/10 * * * *', // every 10 minutes
            numberOfRuns: 3,
            urls: ['http://staging.example.com', 'http://staging.example.com/pricing'],
          },
        ],
      },
      storage: {
        storageMethod: 'sql',
        sqlDialect: 'postgres',
        sqlConnectionSsl: true,
        sqlConnectionUrl: process.env.DATABASE_URL,
        sqlDialectOptions: {
          ssl: true,
        },
        sequelizeOptions: {
          pool: {
            acquire: 30000,
          },
        },
      },
    },
  },
};

Custom Headers for Wizard

If you're running the lhci server behind a reverse proxy or any other component that requires some extra headers you can configure them in the wizard section extraHeaders.

{
  "ci": {
    "wizard": {
      "extraHeaders": "{\"Authorization\": \"Basic content\"}"
    }
  }
}

NOTE: The wizard options will be overwritten by the upload options, to be sure that the wizard options will be used, create a separate config file.

Default LHCI Server for Wizard

If you're running the lhci wizard multiple times, you can configure a default serverBaseUrl to avoid typing it in at each lhci wizard run.

{
  "ci": {
    "wizard": {
      "serverBaseUrl": "https://localhost:3000/"
    }
  }
}

NOTE: The wizard options will be overwritten by the upload options, to be sure that the wizard options will be used, create a separate config file.

YAML Advanced config

ci:
  collect:
    numberOfRuns: 5
    startServerCommand: rails server -e production
    url:
      - http://localhost:3000/
      - http://localhost:3000/pricing
      - http://localhost:3000/support
  assert:
    preset: lighthouse:recommended
    assertions:
      offscreen-images: 'off'
      uses-webp-images: 'off'
      color-contrast: 'off'
      first-contentful-paint:
        - error
        - maxNumericValue: 2000
          aggregationMethod: optimistic
      interactive:
        - error
        - maxNumericValue: 5000
          aggregationMethod: optimistic
  upload:
    target: lhci
    serverBaseUrl: https://lhci.example.com