Test suites for Web platform specs — including WHATWG, W3C, and others
Clone or download
horo-t and chromium-wpt-export-bot Support document.referrer in SXG
Before this CL, CreateRedirectInfo() in signed_exchange_loader.cc doesn't set
redirect_info.new_referrer correctly. So document.referrer was always empty
string after clicking a link of signed exchange.
After this CL, CreateRedirectInfo() returns a RedirectInfo with new_referrer, so
document.referrer will be set correctly.

This CL introduces network::ResourceRequest argument in
PrefetchURLLoader, SignedExchangePrefetchHandler and SignedExchangeLoader.
This value will be used to compute a correct RedirectInfo while handling the
synthesized redirect for signed exchange.

This CL uses "ignoreErrors" flag in generate-test-sxgs.sh while creating invalid
signed exchange files. This flags was introduces by this change in webpackage

Bug: 920905
Change-Id: I52a302d22c375b776874c996638b409cdcba8a9c
Reviewed-on: https://chromium-review.googlesource.com/c/1415245
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Kouhei Ueno <kouhei@chromium.org>
Reviewed-by: Kunihiko Sakamoto <ksakamoto@chromium.org>
Commit-Queue: Tsuyoshi Horo <horo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#625094}
Latest commit 5835a01 Jan 23, 2019
Type Name Latest commit message Commit time
Failed to load latest commit information.
.well-known Origin Policy: Add support for Feature Policy. Nov 19, 2018
2dcontext canvas: Restore the data: URL special case for tainting. Jan 9, 2019
BackgroundSync Remove the idl_test test_name argument (always 'idl_test setup') (#12406 Aug 13, 2018
FileAPI fixup! [FileAPI] Remove reference to non-existent file Nov 26, 2018
IndexedDB [IndexedDB]: Add commit check to aborting txns. Jan 4, 2019
WebCryptoAPI [WebCryptoAPI] Remove race condition (#14291) Dec 10, 2018
WebIDL Request/Response's clone() realm Nov 2, 2018
accelerometer Remove alexshalamov from the suggested reviewers lists (#13706) Oct 25, 2018
accname accname: tweak two tests for clarity Sep 28, 2018
acid Rename of OWNER files to META.yml Jun 12, 2018
ambient-light Remove alexshalamov from the suggested reviewers lists (#13706) Oct 25, 2018
animation-worklet [animation-worklet] clean up wpt tests Jan 17, 2019
annotation-model Add more spec links to META.yml (#12045) Jul 18, 2018
annotation-protocol Add more spec links to META.yml (#12045) Jul 18, 2018
annotation-vocab Remove some suggested reviewers who have asked to be removed (#13796) Oct 30, 2018
apng Add more spec links to META.yml (#12045) Jul 18, 2018
appmanifest Remove the idl_test test_name argument (always 'idl_test setup') (#12406 Aug 13, 2018
audio-output Rename audio-output idlharness test for secure context change (#14337) Dec 3, 2018
background-fetch [Background Fetch] Remove use of chromium specific resource Dec 21, 2018
battery-status [Battery] Correct IDL file name (#12422) Aug 13, 2018
beacon Fix the test to use http://nonexistent.web-platform.test Oct 25, 2018
bluetooth WebBluetooth - clang-format wpt Jan 18, 2019
clear-site-data WPT for Clear-Site-Data executionContexts Aug 2, 2018
client-hints Fix processing of double Content-DPR values and add Content-DPR WPT t… Oct 15, 2018
clipboard-apis Async Clipboard: Automate writeImage/readImage test Jan 19, 2019
common Split fetch CORP tests as HTTP and HTTPS. (#14907) Jan 18, 2019
compat Notify andruud on changes to wpt/css/css-properties-values-api. Aug 30, 2018
conformance-checkers cc Change expected result for xml:base test Dec 18, 2018
console Convert compat+console+fullscreen+storage+url+xhr to idl_test (#12405) Aug 10, 2018
content-security-policy Move CSP check for form-action to be within HTMLFormSubmission to pre… Jan 10, 2019
cookie-store Cookie Store: Test cross-origin frames + service workers. Jan 1, 2019
cookies Remove timeout from promise_test (#14253) Nov 27, 2018
core-aam ARIA: Add team contact to suggested reviewers for wai-aria and core-a… Jul 19, 2018
cors Remove timeout in async_test for miscellaneous tests (#14094) Nov 23, 2018
credential-management Add spec links to META.yml Jul 17, 2018
css Always promote fixed and sticky positioned elements, if they Jan 23, 2019
custom-elements WebKit export of https://bugs.webkit.org/show_bug.cgi?id=183586 (#14721) Jan 5, 2019
device-memory Add spec links to META.yml Jul 17, 2018
docs Change all references of reftest size to be 600x600 Jan 17, 2019
dom Add another test with a HTMLCollection on the prototype chain. Jan 21, 2019
domparsing Insert an error message block when parsing was stopped after an error Oct 25, 2018
domxpath Add more spec links to META.yml (#12045) Jul 18, 2018
dpub-aam Add more spec links to META.yml (#12045) Jul 18, 2018
dpub-aria Add more spec links to META.yml (#12045) Jul 18, 2018
editing Use MoveParagraphWithClones when moving paragraphs to new list items Oct 17, 2018
encoding python3 de-linting (#14973) Jan 22, 2019
encrypted-media Remove timeout from promise_test (#14253) Nov 27, 2018
entries-api webkitRelativePath preserves common ancestors (#13988) Nov 9, 2018
event-timing [EventTiming] Report events without event handlers Dec 12, 2018
eventsource Rewrite `async_test(document.title)` to just `async_test()` (#14232) Nov 27, 2018
feature-policy [ FeaturePolicy ] - Report for "legacy-image-formats" Jan 21, 2019
fetch WebKit export of https://bugs.webkit.org/show_bug.cgi?id=193553 (#14940) Jan 18, 2019
fonts Test that resources fetched by cross-origin CSS are not in the timeli… Jan 3, 2019
fullscreen Fix two fullscreen wpt tests for UAv2. Nov 23, 2018
gamepad Remove the idl_test test_name argument (always 'idl_test setup') (#12406 Aug 13, 2018
generic-sensor Remove alexshalamov from the suggested reviewers lists (#13706) Oct 25, 2018
geolocation-API Remove timeout in async_test for geolocation-API tests Nov 27, 2018
geolocation-sensor Remove the idl_test test_name argument (always 'idl_test setup') (#12406 Aug 13, 2018
graphics-aam Add more spec links to META.yml (#12045) Jul 18, 2018
gyroscope Remove alexshalamov from the suggested reviewers lists (#13706) Oct 25, 2018
hr-time Remove test-level assert property from tests (#14409) Dec 10, 2018
html-longdesc Add more spec links to META.yml (#12045) Jul 18, 2018
html-media-capture Remove the idl_test test_name argument (always 'idl_test setup') (#12406 Aug 13, 2018
html Make a workaround for the test with about:blank onload Jan 22, 2019
idle-detection Idle Detection API: Prototype Jan 18, 2019
imagebitmap-renderingcontext Tweak URLs for directories for parts of WHATWG standards Jul 17, 2018
images Remove reviewers who have not joined the web-platform-tests org (#11888) Jul 11, 2018
inert Move inert tests to top level directory and rename with .tentative Aug 30, 2018
infrastructure Add a infra test for reftest size Jan 17, 2019
input-device-capabilities Convert Input Device Capabilities IDL test to use idl_test (#12576) Aug 27, 2018
input-events Make WPT for InputEvent.inputType of each execCommand should test eac… Jan 8, 2019
interfaces Update interfaces/css-pseudo.idl (#14989) Jan 22, 2019
intersection-observer WebKit export of https://bugs.webkit.org/show_bug.cgi?id=191975 (#14266) Nov 28, 2018
js Add more spec links to META.yml (#12045) Jul 18, 2018
keyboard-lock Remove the idl_test test_name argument (always 'idl_test setup') (#12406 Aug 13, 2018
keyboard-map Remove the idl_test test_name argument (always 'idl_test setup') (#12406 Aug 13, 2018
kv-storage KV Storage: make keys()/values()/entries() async iterators Jan 19, 2019
lifecycle Add some more spec links manually Jul 17, 2018
loading Fix CSSPreloadScanner to avoid missing rules (reland) Nov 27, 2018
longtask-timing address feedback Jan 16, 2019
magnetometer Remove alexshalamov from the suggested reviewers lists (#13706) Oct 25, 2018
mathml Update MathML spec link (#14861) Jan 16, 2019
media-capabilities Media Capabilities: implement response side of Encrypted Media. Nov 28, 2018
media-source MSE: Update one of the wpt mediasource-errors sub-tests Dec 11, 2018
media Ship CreateImageBitmap resize options Aug 13, 2018
mediacapture-depth Add media capture depth dictionary test (#7335) Jan 3, 2019
mediacapture-fromelement Remove Chrome-specific dependency and modernize. Dec 18, 2018
mediacapture-image [Image Capture] Add exposureTime constraint. Sep 18, 2018
mediacapture-record Check that all events are fired as expected for MediaRecorder-stop.html. Jan 15, 2019
mediacapture-streams Fix MediaStream-default-feature-policy.https.html to respect getUserM… Jan 19, 2019
mediasession Remove the idl_test test_name argument (always 'idl_test setup') (#12406 Aug 13, 2018
mimesniff Fetch: Content-Type parsing Nov 27, 2018
mixed-content [WPT] Unify mixed-content and referrer-policy generator scripts Jan 19, 2019
mst-content-hint Enable the "Content hint" attribute of MediaStreamTrack Aug 16, 2018
navigation-timing address feedback Jan 16, 2019
netinfo Remove the idl_test test_name argument (always 'idl_test setup') (#12406 Aug 13, 2018
network-error-logging Fix up a typo in network-error-logging/support/lock.py Nov 19, 2018
notifications Avoid invoking the Notification constructor in service workers (#12500) Aug 15, 2018
offscreen-canvas Tweak URLs for directories for parts of WHATWG standards Jul 17, 2018
old-tests Try less trailing newlines Aug 6, 2018
orientation-event Rewrite `async_test(document.title)` to just `async_test()` (#14232) Nov 27, 2018
orientation-sensor Remove alexshalamov from the suggested reviewers lists (#13706) Oct 25, 2018
origin-policy Feature Policy JS API Update: policy => featurePolicy Jan 4, 2019
page-visibility Remove the idl_test test_name argument (always 'idl_test setup') (#12406 Aug 13, 2018
paint-timing address feedback Jan 16, 2019
payment-handler Remove tests for supportedTypes from payment handler (#13860) Nov 1, 2018
payment-method-basic-card Remove tests for supportedTypes from basic-card (#13859) Nov 2, 2018
payment-method-id Adding test file to the payment-request-id directory (#13229) Sep 26, 2018
payment-request Test payment request is showing boolean (#14297) Jan 18, 2019
performance-timeline address feedback Jan 16, 2019
permissions [Background Fetch] Surface background-fetch permission. Oct 5, 2018
picture-in-picture Fix timeout issue by calling play() Dec 10, 2018
pointerevents [Reland] Synthetic gestures wait on renderer ACK. Jan 21, 2019
pointerlock Change the button type to int in the pointerActionSequence API Nov 6, 2018
portals Revert "Portals: Expose portalHost to portal's browsing context" Jan 19, 2019
preload Add imageSrcset and imageSizes IDL attributes to HTMLLinkElement Nov 27, 2018
presentation-api [presentation-api] Revise the test for reconnecting multiple presenta… Nov 6, 2018
priority-hints Add more suggested reviewers for Priority Hints Aug 7, 2018
proximity Remove the idl_test test_name argument (always 'idl_test setup') (#12406 Aug 13, 2018
push-api Rename idlharness tests for [SecureContext] APIs to .https. (#12353) Aug 8, 2018
quirks [LayoutNG] Don't allow line height quirk inside list items. Dec 20, 2018
referrer-policy [WPT] Unify mixed-content and referrer-policy generator scripts Jan 19, 2019
remote-playback Remove the idl_test test_name argument (always 'idl_test setup') (#12406 Aug 13, 2018
reporting Add Reporting API IDL file + test (#12496) Aug 15, 2018
requestidlecallback Remove test-level assert property from tests (#14409) Dec 10, 2018
resize-observer Remove the idl_test test_name argument (always 'idl_test setup') (#12406 Aug 13, 2018
resource-timing Merge pull request #14867 from cvazac/cvazac/supportedEntryTypes Jan 18, 2019
resources Revamp how idlharness.js handles iterable declarations (#14629) Jan 15, 2019
screen-capture Implement getDisplayMedia() and update related wpt tests. Dec 29, 2018
screen-orientation Remove the idl_test test_name argument (always 'idl_test setup') (#12406 Aug 13, 2018
scroll-animations [ScrollTimeline] Upstream root scroller currentTime test to WPT Dec 10, 2018
secure-contexts Rewrite secure-contexts/idlharness.any.js to use idl_test (#12386) Aug 9, 2018
selection Count partial mixins as tested deps (#13878) Nov 9, 2018
server-timing Make Server-Timing tests more resilient (#13789) Nov 2, 2018
service-workers [ServiceWorker] Revise wpt worker-interception.https.html Jan 18, 2019
shadow-dom Retarget results of offset* DOM APIs. Jan 9, 2019
shape-detection Add some more spec links manually Jul 17, 2018
signed-exchange Support document.referrer in SXG Jan 23, 2019
speech-api Remove timeout from async_test for argument form. (#14273) Nov 29, 2018
storage Quota: Test service worker registrations in StorageEstimate.usageDeta… Jan 16, 2019
streams Part 1: Adapt stream tests to run in the shell. Dec 19, 2018
subresource-integrity Remove some suggested reviewers who have asked to be removed (#13796) Oct 30, 2018
svg-aam Add more spec links to META.yml (#12045) Jul 18, 2018
svg SVG Interactivity: onwheel attribute (#14876) Jan 21, 2019
tools Update mozinstall from 1.16.0 to 2.0.0 (#14941) Jan 21, 2019
touch-events Remove the idl_test test_name argument (always 'idl_test setup') (#12406 Aug 13, 2018
trusted-types Store TrustedURL and TrustedScriptURL contents as string, take 2 Jan 18, 2019
uievents Modify the web platform tests with mouse inputs to use TestDriver Nov 27, 2018
upgrade-insecure-requests [wpt/upgrade-insecure-requests] Add worker/worklet tests Jan 10, 2019
url Remove leading question mark when constructing URLSearchParams Dec 25, 2018
user-timing address feedback Jan 16, 2019
vibration Rewrite Vibration API IDL test to use idl_test (#12433) Aug 14, 2018
visual-viewport Add spec links to META.yml Jul 17, 2018
wai-aria Add IDL tests for WAI-ARIA (#12822) Sep 4, 2018
wake-lock Wake Lock API: Add checks for feature policy. Dec 12, 2018
wasm Remove stray property from memory/constructor.any.js. Dec 7, 2018
web-animations Part 2: Implement Animate for track lists on grid-template-{columns|r… Jan 14, 2019
web-locks Web Locks API: Fix IDL glitch Oct 22, 2018
web-nfc Remove alexshalamov from the suggested reviewers lists (#13706) Oct 25, 2018
web-share WebShare: canShare() method in Level 2 Jan 21, 2019
webaudio Don't overflow when event times are very close in time Jan 16, 2019
webauthn ArrayBuffer(0) is implementation specific, so removed (#14610) Dec 20, 2018
webdriver [wdspec] Add tests for "New Window" command. Jan 20, 2019
webgl Update WebGL IDL files + tests (#12499) Aug 15, 2018
webmessaging Implement PostMessageOptions for Window Nov 2, 2018
webmidi Rename idlharness.window.js to idlharness.https.window.js (#13634) Oct 20, 2018
webrtc-identity Add jan-ivar as reviewer. (#13957) Nov 6, 2018
webrtc-quic Adds pre shared key support to RTCQuicTransport. Jan 19, 2019
webrtc-stats Merge pull request #13922 from youennf/no-address-member-in-remote-ca… Jan 17, 2019
webrtc Fix RTCRtpReceiver-getContributingSources.https.html flake. Jan 21, 2019
websockets Remove unnecessary parameters from async_test Nov 21, 2018
webstorage Fix assert for StorageEvent constructor test (#13405) Oct 6, 2018
webusb Refactor device_manager.mojom Jan 8, 2019
webvr Add more spec links to META.yml (#12045) Jul 18, 2018
webvtt fix video reference in webvtt rendering tests Nov 7, 2018
webxr Move views array from XRFrame to XRViewerPose. Jan 14, 2019
workers Add worker WPT test writing guide and examples Jan 18, 2019
worklets [wpt/upgrade-insecure-requests] Add worker/worklet tests Jan 10, 2019
x-frame-options Fix x-frame-options WPTs Sep 19, 2018
xhr XMLHttpRequest: check if entry lists associated to new FormData insta… Jan 11, 2019
.azure-pipelines.yml [Azure Pipelines] Run full daily runs of Safari Technology Preview (#… Jan 9, 2019
.codecov.yml Add codecov configutation. (#5623) Apr 24, 2017
.gitignore Fix #11075: Add name constraints to CA (#14206) Dec 20, 2018
.gitmodules Fix #7200: Update vendored html5lib to 1.0.1 Jun 6, 2018
.pyup.yml Add requirements_flake8.txt to .pyup.yml Nov 5, 2018
.taskcluster.yml Run affected tests on Taskcluster without changes Dec 6, 2018
.travis.yml Fix #7660: Remove Travis stability checks (Chrome Dev + Firefox Night… Dec 20, 2018
CODEOWNERS Add CODEOWNERS to prevent submodule issues May 24, 2018
CONTRIBUTING.md Use https://web-platform-tests.org (#10925) May 9, 2018
LICENSE.md Fix the first header in the license file (#5244) Mar 28, 2017
README.md [README] Exclude label:vendor-imports in PR links Sep 28, 2018
check_stability.ini Implement --affected as a flag of `wpt run` Dec 10, 2018
lint.whitelist Mark font-display feature policy tests as tentative Jan 22, 2019
serve.py Add a warning when running ./serve when tools.serve cannot be imported ( Oct 30, 2016
server-side.md Make tests self-hosting Jan 6, 2014
testharness_runner.html Add testharness_runner file here for now. Apr 17, 2015
update-built-tests.sh Delete unbuilt css3-selectors tests; move built tests up Aug 24, 2018
wpt Add a wpt command as a frontend to all cli interactions. Jul 26, 2017
wpt.py Allow |python wpt <command>| to work on Windows. Aug 16, 2017


The web-platform-tests Project IRC chat

The web-platform-tests Project is a W3C-coordinated attempt to build a cross-browser testsuite for the Web-platform stack. Writing tests in a way that allows them to be run in all browsers gives browser projects confidence that they are shipping software that is compatible with other implementations, and that later implementations will be compatible with their implementations. This in turn gives Web authors/developers confidence that they can actually rely on the Web platform to deliver on the promise of working across browsers and devices without needing extra layers of abstraction to paper over the gaps left by specification editors and implementors.

Setting Up the Repo

Clone or otherwise get https://github.com/web-platform-tests/wpt.

Note: because of the frequent creation and deletion of branches in this repo, it is recommended to "prune" stale branches when fetching updates, i.e. use git pull --prune (or git fetch -p && git merge).

Running the Tests

The tests are designed to be run from your local computer. The test environment requires Python 2.7+ (but not Python 3.x).

On Windows, be sure to add the Python directory (c:\python2x, by default) to your %Path% Environment Variable, and read the Windows Notes section below.

To get the tests running, you need to set up the test domains in your hosts file.

The necessary content can be generated with ./wpt make-hosts-file; on Windows, you will need to precede the prior command with python or the path to the Python binary (python wpt make-hosts-file).

For example, on most UNIX-like systems, you can setup the hosts file with:

./wpt make-hosts-file | sudo tee -a /etc/hosts

And on Windows (this must be run in a PowerShell session with Administrator privileges):

python wpt make-hosts-file | Out-File $env:systemroot\System32\drivers\etc\hosts -Encoding ascii -Append

If you are behind a proxy, you also need to make sure the domains above are excluded from your proxy lookups.

Running Tests Manually

The test server can be started using

./wpt serve

On Windows: You will need to precede the prior command with python or the path to the python binary.

python wpt serve

This will start HTTP servers on two ports and a websockets server on one port. By default the web servers start on ports 8000 and 8443 and the other ports are randomly-chosen free ports. Tests must be loaded from the first HTTP server in the output. To change the ports, create a config.json file in the wpt root directory, and add port definitions of your choice e.g.:

  "ports": {
    "http": [1234, "auto"],

After your hosts file is configured, the servers will be locally accessible at:

https://web-platform.test:8443/ *

*See Trusting Root CA

Running Tests Automatically

Tests can be run automatically in a browser using the run command of the wpt script in the root of the checkout. This requires the hosts file setup documented above, but you must not have the test server already running when calling wpt run. The basic command line syntax is:

./wpt run product [tests]

On Windows: You will need to precede the prior command with python or the path to the python binary.

python wpt run product [tests]

where product is currently firefox or chrome and [tests] is a list of paths to tests. This will attempt to automatically locate a browser instance and install required dependencies. The command is very configurable; for example to specify a particular binary use wpt run --binary=path product. The full range of options can be see with wpt run --help and wpt run --wptrunner-help.

Not all dependencies can be automatically installed; in particular the certutil tool required to run https tests with Firefox must be installed using a system package manager or similar.

On Debian/Ubuntu certutil may be installed using:

sudo apt install libnss3-tools

And on macOS with homebrew using:

brew install nss

On other platforms, download the firefox archive and common.tests.tar.gz archive for your platform from Mozilla CI.

Then extract certutil[.exe] from the tests.tar.gz package and libnss3[.so|.dll|.dynlib] and put the former on your path and the latter on your library path.

Command Line Tools

The wpt command provides a frontend to a variety of tools for working with and running web-platform-tests. Some of the most useful commands are:

  • wpt serve - For starting the wpt http server
  • wpt run - For running tests in a browser
  • wpt lint - For running the lint against all tests
  • wpt manifest - For updating or generating a MANIFEST.json test manifest
  • wpt install - For installing the latest release of a browser or webdriver server on the local machine.


Some optional components of web-platform-tests (test components from third party software and pieces of the CSS build system) are included as submodules. To obtain these components run the following in the root of your checkout:

git submodule update --init --recursive

Prior to commit 39d07eb01fab607ab1ffd092051cded1bdd64d78 submodules were required for basic functionality. If you are working with an older checkout, the above command is required in all cases.

When moving between a commit prior to 39d07eb and one after it git may complain

$ git checkout master
error: The following untracked working tree files would be overwritten by checkout:

...followed by a long list of files. To avoid this error, remove the resources and tools directories before switching branches:

$ rm -r resources/ tools/
$ git checkout master
Switched to branch 'master'
Your branch is up-to-date with 'origin/master'

When moving in the opposite direction, i.e. to a commit that does have submodules, you will need to git submodule update, as above. If git throws an error like:

fatal: No url found for submodule path 'resources/webidl2/test/widlproc' in .gitmodules
Failed to recurse into submodule path 'resources/webidl2'
fatal: No url found for submodule path 'tools/html5lib' in .gitmodules
Failed to recurse into submodule path 'resources'
Failed to recurse into submodule path 'tools'

...then remove the tools and resources directories, as above.

Windows Notes

On Windows wpt commands must be prefixed with python or the path to the python binary (if python is not in your %PATH%).

python wpt [command]

Alternatively, you may also use Bash on Ubuntu on Windows in the Windows 10 Anniversary Update build, then access your windows partition from there to launch wpt commands.

Please make sure git and your text editor do not automatically convert line endings, as it will cause lint errors. For git, please set git config core.autocrlf false in your working tree.


By default pre-generated certificates for the web-platform.test domain are provided in tools/certs. If you wish to generate new certificates for any reason it's possible to use OpenSSL when starting the server, or starting a test run, by providing the --ssl-type=openssl argument to the wpt serve or wpt run commands.

If you installed OpenSSL in such a way that running openssl at a command line doesn't work, you also need to adjust the path to the OpenSSL binary. This can be done by adding a section to config.json like:

"ssl": {"openssl": {"binary": "/path/to/openssl"}}

On Windows using OpenSSL typically requires installing an OpenSSL distribution. Shining Light provide a convenient installer that is known to work, but requires a little extra setup, i.e.:

Run the installer for Win32_OpenSSL_v1.1.0b (30MB). During installation, change the default location for where to Copy OpenSSL Dlls from the System directory to the /bin directory.

After installation, ensure that the path to OpenSSL (typically, this will be C:\OpenSSL-Win32\bin) is in your %Path% Environment Variable. If you forget to do this part, you will most likely see a 'File Not Found' error when you start wptserve.

Finally, set the path value in the server configuration file to the default OpenSSL configuration file location. To do this create a file called config.json. Then add the OpenSSL configuration below, ensuring that the key ssl/openssl/base_conf_path has a value that is the path to the OpenSSL config file (typically this will be C:\\OpenSSL-Win32\\bin\\openssl.cfg):

  "ssl": {
    "type": "openssl",
    "encrypt_after_connect": false,
    "openssl": {
      "openssl_binary": "openssl",
      "base_path: "_certs",
      "force_regenerate": false,
      "base_conf_path": "C:\\OpenSSL-Win32\\bin\\openssl.cfg"

Trusting Root CA

To prevent browser SSL warnings when running HTTPS tests locally, the web-platform-tests Root CA file cacert.pem in tools/certs must be added as a trusted certificate in your OS/browser.

NOTE: The CA should not be installed in any browser profile used outside of tests, since it may be used to generate fake certificates. For browsers that use the OS certificate store, tests should therefore not be run manually outside a dedicated OS instance (e.g. a VM). To avoid this problem when running tests in Chrome or Firefox use wpt run, which disables certificate checks and therefore doesn't require the root CA to be trusted.


The master branch is automatically synced to http://w3c-test.org/.

Pull requests are automatically mirrored except those that modify sensitive resources (such as .py). The latter require someone with merge access to comment with "LGTM" or "w3c-test:mirror" to indicate the pull request has been checked.

Finding Things

Each top-level directory matches the shortname used by a standard, with some exceptions. (Typically the shortname is from the standard's corresponding GitHub repository.)

For some of the specifications, the tree under the top-level directory represents the sections of the respective documents, using the section IDs for directory names, with a maximum of three levels deep.

So if you're looking for tests in HTML for "The History interface", they will be under html/browsers/history/the-history-interface/.

Various resources that tests depend on are in common, images, and fonts.


In the vast majority of cases the only upstream branch that you should need to care about is master. If you see other branches in the repository, you can generally safely ignore them.


Save the Web, Write Some Tests!

Absolutely everyone is welcome (and even encouraged) to contribute to test development, so long as you fulfill the contribution requirements detailed in the Contributing Guidelines. No test is too small or too simple, especially if it corresponds to something for which you've noted an interoperability bug in a browser.

The way to contribute is just as usual:

  • Fork this repository (and make sure you're still relatively in sync with it if you forked a while ago).
  • Create a branch for your changes: git checkout -b topic.
  • Make your changes.
  • Run the lint script described below.
  • Commit locally and push that to your repo.
  • Send in a pull request based on the above.

Issues with web-platform-tests

If you spot an issue with a test and are not comfortable providing a pull request per above to fix it, please file a new issue. Thank you!

Lint tool

We have a lint tool for catching common mistakes in test files. You can run it manually by starting the lint executable from the root of your local web-platform-tests working directory like this:

./wpt lint

The lint tool is also run automatically for every submitted pull request, and reviewers will not merge branches with tests that have lint errors, so you must fix any errors the lint tool reports.

In the unusual case of error reports for things essential to a certain test or that for other exceptional reasons shouldn't prevent a merge of a test, update and commit the lint.whitelist file in the web-platform-tests root directory to suppress the error reports.

For more details, see the lint-tool documentation.

Adding command-line scripts ("tools" subdirs)

Sometimes you may want to add a script to the repository that's meant to be used from the command line, not from a browser (e.g., a script for generating test files). If you want to ensure (e.g., for security reasons) that such scripts won't be handled by the HTTP server, but will instead only be usable from the command line, then place them in either:

  • the tools subdir at the root of the repository, or

  • the tools subdir at the root of any top-level directory in the repository which contains the tests the script is meant to be used with

Any files in those tools directories won't be handled by the HTTP server; instead the server will return a 404 if a user navigates to the URL for a file within them.

If you want to add a script for use with a particular set of tests but there isn't yet any tools subdir at the root of a top-level directory in the repository containing those tests, you can create a tools subdir at the root of that top-level directory and place your scripts there.

For example, if you wanted to add a script for use with tests in the notifications directory, create the notifications/tools subdir and put your script there.

Test Review

We can sometimes take a little while to go through pull requests because we have to go through all the tests and ensure that they match the specification correctly. But we look at all of them, and take everything that we can.

META.yml files are used only to indicate who should be notified of pull requests. If you are interested in receiving notifications of proposed changes to tests in a given directory, feel free to add yourself to the META.yml file. Anyone with expertise in the specification under test can approve a pull request. In particular, if a test change has already been adequately reviewed "upstream" in another repository, it can be pushed here without any further review by supplying a link to the upstream review.

Search filters to find things to review:

Getting Involved

If you wish to contribute actively, you're very welcome to join the public-test-infra@w3.org mailing list (low traffic) by signing up to our mailing list. The mailing list is archived.

Join us on irc #testing (irc.w3.org, port 6665). The channel is archived.