Cross-platform WebPageTest agent
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docker/linux-headless docker: Less verbose output by default Sep 25, 2017
docs Added a script for updating the agent when running it as a systemd se… Jun 20, 2018
gnirehtet Updated gnirehtet for arm Oct 18, 2018
internal Exit the agent if an adb reboot doesn't restore connectivity Oct 19, 2018
misc/adb/arm Made 64-bit adb executable May 19, 2018
scripts Added a script for updating the agent when running it as a systemd se… Jun 20, 2018
simple-rt Simplified ipfw management Jun 9, 2017
vpn-reverse-tether Added binaries for vpn-reverse-tether Nov 20, 2017
ws4py Switched to ws4py from websocket-client Mar 27, 2017
.dockerignore Don't include git repo in docker image anymore May 3, 2017
.gitignore Added chunk timings for Firefox Sep 22, 2018
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LICENSE Initial skeleton for new agent Feb 13, 2017 fixed typos/capitalization Jul 13, 2018
alive.bat Updated the Windows watchdog to use the full path Mar 10, 2018 Another slew of PEP8/flake8 fixes in /internal - more to come Oct 12, 2018 Added a shell script for watchdog integration Jan 11, 2018
browsers.ini.sample Added support for Firefox ESR May 15, 2018 Rebuild the font cache as part of the centos install Mar 6, 2018 Added net-tools to the ubuntu install for route support Jun 20, 2018 Mark the agent as alive in case the phone is having issues (to preven… Oct 17, 2018


Cross-platform WebPageTest agent

Supported Platforms/Browsers

Chrome is the only browser that currently supports manipulating requests (changing headers, blocking requests, etc). Chrome, IE and Microsoft Edge are the only browsers that currently support capturing response bodies and running optimization checks. All browsers should support basic page loading, scripts and video capture on all platforms. Traffic-shaping is supported on all platforms as well.

Linux (with display or headless with Xvfb)

  • Chrome (Stable, Beta and Unstable)
  • Firefox (Stable and Nightly)
  • Opera (Stable, Beta and Developer)


  • Chrome (Stable, Beta, Dev and Canary)
  • Firefox (Stable, ESR, Developer Edition, Beta and Nightly)
  • Microsoft Edge
  • Internet Explorer
  • Opera (Stable, Beta and Developer)


  • Chrome (Stable and Canary)
  • Firefox (Stable and Nightly)

Android (requires a tethered host - Raspberry Pi's preferred)

  • Chrome (Stable, Beta, Dev and Canary)
  • Several browsers run as "black box" tests (single page load, visual metrics only):
    • Chrome (Stable, Beta, Dev and Canary)
    • Samsung Browser
    • Opera
    • Opera Mini
    • UC Browser
    • UC Mini
    • Firefox (Stable and Beta)

Known Issues

  • Internet Explorer does not support manipulating requests (adding headers, blocking requests, etc)


  • Install docs are here

Run with docker

Check out the docker instructions for information on how to run the agent in a docker container.

Command-line options

Basic agent config

  • -v : Increase verbosity (specify multiple times for more). -vvvv for full debug output.
  • --name : Agent name (defaults to the machine's hostname).
  • --exit : Exit after the specified number of minutes.
    • Useful for running in a shell script that does some maintenance or updates periodically (like hourly).
  • --dockerized: The agent is running inside a docker container.
  • --ec2 : Load config settings from EC2 user data.
  • --gce : Load config settings from GCE user data.
  • --log : Log critical errors to the given file.

Video capture/display settings

  • --xvfb : Use an xvfb virtual display for headless testing (Linux only).
  • --fps : Video capture frame rate (defaults to 10). Valid range is 1-60. (Linux only).

Server/location configuration

  • --server (required): URL for WebPageTest work (i.e.
  • --validcertificate: Validate server certificates (HTTPS server, defaults to False).
  • --location (required): Location ID (as configured in locations.ini on the server).
  • --key : Location key (if configured in locations.ini).

Traffic-shaping options (defaults to host-based)

  • --shaper : Override default traffic shaper. Current supported values are:
    • none - Disable traffic-shaping (i.e. when root is not available).
    • netem,<interface> - Use NetEm for bridging rndis traffic (specify outbound interface). i.e. --shaper netem,eth0
    • remote,<server>,<down pipe>,<up pipe> - Connect to the remote server over ssh and use pre-configured dummynet pipes (ssh keys for root user should be pre-authorized).

CPU Throttling

  • --throttle: Enable cgroup-based CPU throttling for mobile emulation (Linux only).

Android testing options

  • --android : Run tests on an attached android device.
  • --device : Device ID (only needed if more than one android device attached).
  • --gnirehtet : Use gnirehtet for reverse-tethering. You will need to manually approve the vpn once per mobile device. Valid options are:
    • ,: i.e. --gnirehtet eth0,
  • --vpntether : (Android < 7) Use vpn-reverse-tether for reverse-tethering. This is the recommended way to reverse-tether devices. You will need to manually approve the vpn once per mobile device. Valid options are:
    • ,: i.e. --vpntether eth0,
  • --simplert : Use SimpleRT for reverse-tethering. The APK should be installed manually (adb install simple-rt/simple-rt-1.1.apk) and tested once manually (./simple-rt -i eth0 then disconnect and re-connect phone) to dismiss any system dialogs. The ethernet interface and DNS server should be passed as options:
    • ,: i.e. --simplert eth0,
  • --rndis : (deprecated) Enable reverse-tethering over rndis (Android < 6.0). Valid options are:
    • /,,,: Static Address. i.e. --rndis,,,
    • dhcp

Options for authenticating the agent with the server:

  • --username : User name if using HTTP Basic auth with WebPageTest server.
  • --password : Password if using HTTP Basic auth with WebPageTest server.
  • --cert : Client certificate if using certificates to authenticate the WebPageTest server connection.
  • --certkey : Client-side private key (if not embedded in the cert).

Currently supported features

  • Feature complete except as noted below (for Windows, Linux, Mac and Android devices)
  • Supported Script Commands:
    • navigate
    • exec (execAndWait)
    • block
    • sleep
    • logData
    • combineSteps
    • setEventName
    • setUserAgent
    • setBrowserSize
    • setViewportSize
    • setDeviceScaleFactor
    • setActivityTimeout
    • setTimeout
    • blockDomains
    • blockDomainsExcept
    • setDns
    • setDnsName
    • setHeader
    • addHeader (can not add multiple values for the same header, effectively the same as setHeader)
    • resetHeaders
    • setCookie
    • setABM
    • click (clickAndWait)
    • selectValue
    • sendClick
    • setInnerHTML
    • setInnerText
    • setValue
    • submitForm

Not yet supported (actively being worked on)

  • Browser installs/updates
  • Windows general cleanup/health (temp files, downloads, killing processes, etc)
  • Script Commands:
    • firefoxPref

Not Supported (no plans to implement)

  • Script Commands:
    • sendKeyDown
    • setDOMElement
    • waitForComplete
    • overrideHostUrl
    • ignoreErrors
    • logErrors
    • loadFile
    • loadVariables
    • minInterval
    • endInterval
    • expireCache
    • requiredRequest
    • setDOMRequest
    • waitForJSDone (change semantics to console log message)
    • overrideHost (depends on support being added to dev tools)
    • if/else/endif