Documentation / Configuration


Configuration is highly configurable, let’s check it out!

The options

You have the following options when running within docker (run docker run sitespeedio/ --help to get the list on your command line):

bin/sitespeed.js [options] <url>/<file>

  --browsertime.browser, -b, --browser                                 Choose which Browser to use when you test.  [choices: "chrome", "firefox"] [default: "chrome"]
  --browsertime.iterations, -n                                         How many times you want to test each page  [default: 3]
  --browsertime.connectivity.profile, -c, --connectivity               The connectivity profile.  [choices: "3g", "3gfast", "3gslow", "3gem", "2g", "cable", "native", "custom"] [default: "native"]
  --browsertime.connectivity.downstreamKbps, --downstreamKbps          This option requires --connectivity be set to "custom".
  --browsertime.connectivity.upstreamKbps, --upstreamKbps              This option requires --connectivity be set to "custom".
  --browsertime.connectivity.latency, --latency                        This option requires --connectivity be set to "custom".
  --browsertime.connectivity.engine                                    Throttle works on Mac and tc based Linux (it is experimental so please use with care). Use external if you set the connectivity outside of Browsertime. The best way do to this is described in  [choices: "throttle", "external"] [default: "external"]
  --browsertime.pageCompleteCheck, --pageCompleteCheck                 Supply a Javascript that decides when the browser is finished loading the page and can start to collect metrics. The Javascript snippet is repeatedly queried to see if page has completed loading (indicated by the script returning true). Use it to fetch timings happening after the loadEventEnd.
  --browsertime.script, --script                                       Add custom Javascript that collect metrics and run after the page has finished loading. Note that --script can be passed multiple times if you want to collect multiple metrics. The metrics will automatically be pushed to the summary/detailed summary and each individual page + sent to Graphite/InfluxDB.
  --browsertime.selenium.url                                           Configure the path to the Selenium server when fetching timings using browsers. If not configured the supplied NodeJS/Selenium version is used.
  --browsertime.viewPort, --viewPort                                   The browser view port size WidthxHeight like 400x300  [default: "1366x708"]
  --browsertime.userAgent, --userAgent                                 The full User Agent string, defaults to the User Agent used by the browsertime.browser option.
  --browsertime.preScript, --preScript                                 Selenium script(s) to run before you test your URL (use it for login, warm the cache, etc). Note that --preScript can be passed multiple times.
  --browsertime.postScript, --postScript                               Selenium script(s) to run after you test your URL (use it for logout etc). Note that --postScript can be passed multiple times.
  --browsertime.delay, --delay                                         Delay between runs, in milliseconds. Use it if your web server needs to rest between runs :)
  --browsertime.pageLoadStrategy, --pageLoadStrategy                   The Page Load Strategy decides when you have control of the page load. Default is normal meaning you will have control after onload. You can change that to none to get control direct after navigation.  [choices: "normal", "none"] [default: "normal"]
  --browsertime.visualMetrics, --visualMetrics, --speedIndex           Calculate Visual Metrics like SpeedIndex, First Visual Change and Last Visual Change. Requires FFMpeg and Python dependencies  [boolean], --video                                         Record a video and store the video. Set it to false to remove the video that is created by turning on visualMetrics. To remove fully turn off video recordings, make sure to set video and visualMetrics to false. Requires FFMpeg to be installed.  [boolean]
  --browsertime.videoParams.framerate, --videoParams.framerate, --fps  Frames per second in the video  [default: 30]
  --browsertime.videoParams.crf, --videoParams.crf                     Constant rate factor for the end result video, see  [default: 23]
  --browsertime.videoParams.addTimer, --videoParams.addTimer           Add timer and metrics to the video  [boolean] [default: true]
  --browsertime.userTimingWhitelist, --userTimingWhitelist             This option takes a regex that will whitelist which userTimings to capture in the results. All userTimings are captured by default. T
  --browsertime.requestheader, -r, --requestheader                     Request header that will be added to the request. Add multiple instances to add multiple request headers. Use the following format key:value
  --browsertime.block, --block                                         Domain to block. Add multiple instances to add multiple domains that will be blocked.
  --browsertime.basicAuth, --basicAuth                                 Use it if your server is behind Basic Auth. Format: username@password.

  --browsertime.firefox.includeResponseBodies, --firefox.includeResponseBodies  Include response bodies in HAR  [choices: "none", "all", "html"] [default: "none"]
  --browsertime.firefox.nightly, --firefox.nightly                              Use Firefox Nightly. Works on OS X. For Linux you need to set the binary path.  [boolean]
  --browsertime.firefox.beta, --firefox.beta                                    Use Firefox Beta. Works on OS X. For Linux you need to set the binary path.  [boolean]
  --browsertime.firefox.developer, --firefox.developer                          Use Firefox Developer. Works on OS X. For Linux you need to set the binary path.  [boolean]
  --browsertime.firefox.binaryPath, --firefox.binaryPath                        Path to custom Firefox binary (e.g. Firefox Nightly). On OS X, the path should be to the binary inside the app bundle, e.g. /Applications/
  --browsertime.firefox.preference, --firefox.preference                        Extra command line arguments to pass Firefox preferences by the format key:value To add multiple preferences, repeat --firefox.preference once per argument.
  --browsertime.firefox.acceptInsecureCerts, --firefox.acceptInsecureCerts      Accept insecure certs  [boolean]
  --browsertime.firefox.collectMozLog, --firefox.collectMozLog                  Collect the MOZ HTTP log  [boolean]

Chrome, --chrome.args                                  Extra command line arguments to pass to the Chrome process. Always leave out the starting -- (--no-sandbox will be no-sandbox). To add multiple arguments to Chrome, repeat once per argument., --chrome.timeline                          Collect the timeline data. Drag and drop the JSON in your Chrome detvools timeline panel or check out the CPU metrics.  [boolean],            Run Chrome on your Android device. Set to for default Chrome version. You need to run adb start-server before you start.,  Choose which device to use. If you do not set it, the first found device will be used., --chrome.collectNetLog                Collect network log from Chrome and save to disk.  [boolean], --chrome.traceCategories            Set the trace categories.  [string], --chrome.collectConsoleLog        Collect Chromes console log and save to disk.  [boolean], --chrome.binaryPath                      Path to custom Chrome binary (e.g. Chrome Canary). On OS X, the path should be to the binary inside the app bundle, e.g. "/Applications/Google Chrome Chrome Canary"

  --browsertime.proxy.http, --proxy.http    Http proxy (host:port)  [string]
  --browsertime.proxy.https, --proxy.https  Https proxy (host:port)  [string]

  --crawler.depth, -d     How deep to crawl (1=only one page, 2=include links from first page, etc.)
  --crawler.maxPages, -m  The max number of pages to test. Default is no limit.

Graphite                The Graphite host used to store captured metrics.
  --graphite.port                The Graphite port used to store captured metrics.  [default: 2003]
  --graphite.auth                The Graphite user and password used for authentication. Format: user:password
  --graphite.httpPort            The Graphite port used to access the user interface and send annotations event  [default: 8080]
  --graphite.webHost             The graphite-web host. If not specified will be used.
  --graphite.namespace           The namespace key added to all captured metrics.  [default: "sitespeed_io.default"]
  --graphite.includeQueryParams  Whether to include query parameters from the URL in the Graphite keys or not  [boolean] [default: false]
  --graphite.arrayTags           Send the tags as Array or a String. In Graphite 1.0 the tags is a array. Before a String  [boolean] [default: true]
  --graphite.statsd              Uses the StatsD interface  [boolean] [default: false]
  --graphite.bulkSize            Break up number of metrics to send with each request.  [number] [default: null]

  --plugins.list    List all configured plugins in the log.  [boolean]
  --plugins.add     Extra plugins that you want to run. Relative or absolute path to the plugin. Specify multiple plugin names separated by comma, or repeat the --plugins.add option
  --plugins.remove  Extra plugins that you want to run. Relative or absolute path to the plugin. Specify multiple plugin names separated by comma, or repeat the --plugins.remove option

  --budget.configPath        Path to the JSON budget file.
  --budget.suppressExitCode  By default returns a failure exit code, if the budget fails. Set this to true and will return exit code 0 independent of the budget.
  --budget.config            The JSON budget config as a string.
  --budget.output            The output format of the budget.  [choices: "junit", "tap"]

  --browsertime.screenshotParams.type, --screenshot.type                                  Set the file type of the screenshot  [choices: "png", "jpg"] [default: "png"]
  --browsertime.screenshotParams.png.compressionLevel, --screenshot.png.compressionLevel  zlib compression level  [default: 6]
  --browsertime.screenshotParams.jpg.quality, --screenshot.jpg.quality                    Quality of the JPEG screenshot. 1-100  [default: 80]
  --browsertime.screenshotParams.maxSize, --screenshot.maxSize                            The max size of the screenshot (width and height).  [default: 2000]

  --influxdb.protocol            The protocol used to store connect to the InfluxDB host.  [default: "http"]                The InfluxDB host used to store captured metrics.
  --influxdb.port                The InfluxDB port used to store captured metrics.  [default: 8086]
  --influxdb.username            The InfluxDB username for your InfluxDB instance.
  --influxdb.password            The InfluxDB password for your InfluxDB instance.
  --influxdb.database            The database name used to store captured metrics.  [default: "sitespeed"]
  --influxdb.tags                A comma separated list of tags and values added to each metric  [default: "category=default"]
  --influxdb.includeQueryParams  Whether to include query parameters from the URL in the InfluxDB keys or not  [boolean] [default: false]
  --influxdb.groupSeparator      Choose which character that will seperate a group/domain. Default is underscore, set it to a dot if you wanna keep the original domain name.  [default: "_"]

  --metrics.list        List all possible metrics in the data folder (metrics.txt).  [boolean] [default: false]
  --metrics.filterList  List all configured filters for metrics in the data folder (configuredMetrics.txt)  [boolean] [default: false]
  --metrics.filter      Add/change/remove filters for metrics. If you want to send all metrics, use: *+ . If you want to remove all current metrics and send only the coach score: *- coach.summary.score.*  [array]

WebPageTest               The domain of your WebPageTest instance.  [default: ""]
  --webpagetest.key                The API key for you WebPageTest instance.
  --webpagetest.location           The location for the test  [default: "Dulles:Chrome"]
  --webpagetest.connectivity       The connectivity for the test.  [default: "Cable"]
  --webpagetest.runs               The number of runs per URL.  [default: 3]
  --webpagetest.custom             Execute arbitrary Javascript at the end of a test to collect custom metrics.
  --webpagetest.file               Path to a script file
  --webpagetest.script             The WebPageTest script as a string.
  --webpagetest.includeRepeatView  Do repeat or single views  [boolean] [default: false]
  --webpagetest.private            Wanna keep the runs private or not  [boolean] [default: true]
  --webpagetest.timeline           Activates Chrome tracing and get the devtools.timeline (only works for Chrome).  [boolean] [default: false]

  --slack.hookUrl       WebHook url for the Slack team (check https://<your team>
  --slack.userName      User name to use when posting status to Slack.  [default: ""]       The slack channel without the # (if something else than the default channel for your hook).
  --slack.type          Send summary for a run, metrics from all URLs, only on errors or all to Slack.  [choices: "summary", "url", "error", "all"] [default: "all"]
  --slack.limitWarning  The limit to get a warning in Slack using the limitMetric  [default: 90]
  --slack.limitError    The limit to get a error in Slack using the limitMetric  [default: 80]
  --slack.limitMetric   The metric that will be used to set warning/error  [choices: "coachScore", "speedIndex", "firstVisualChange"] [default: "coachScore"]

  --s3.key                The S3 key
  --s3.secret             The S3 secret
  --s3.bucketname         Name of the S3 bucket
  --s3.path               Override the default folder path in the bucket where the results are uploaded. By default it's "DOMAIN_OR_FILENAME/TIMESTAMP", or the name of the folder if --outputFolder is specified.
  --s3.region             The S3 region. Optional depending on your settings.
  --s3.acl                The S3 canned ACL to set. Optional depending on your settings.
  --s3.removeLocalResult  Remove all the local result files after they have been uploaded to S3.  [boolean] [default: false]
  --s3.params             Extra params passed when you do the S3.upload: - Example: --s3.params.Expires=31536000 to set expire to one year.
  --s3.options            Extra options passed when you create the S3 object: - Example: add --s3.options.apiVersion=2006-03-01 to lock to a specific API version.

  --html.showAllWaterfallSummary  Set to true to show all waterfalls on page summary HTML report  [boolean] [default: false]
  --html.fetchHARFiles            Set to true to load HAR files using fetch instead of including them in the HTML. Turn this on if serve your pages using a server.  [boolean] [default: false]
  --html.logDownloadLink          Adds a link in the HTML so you easily can download the logs from the run. If your server is public, be careful so you don't log passwords etc  [boolean] [default: false]
  --html.topListSize              Maximum number of assets to include in each toplist in the toplist tab  [default: 10]

  --summary         Show brief text summary to stdout  [boolean] [default: false]
  --summary-detail  Show longer text summary to stdout  [boolean] [default: false]

  --version, -V                       Show version number  [boolean]
  --debug                             Debug mode logs all internal messages to the console.  [boolean] [default: false]
  --verbose, -v                       Verbose mode prints progress messages to the console. Enter up to three times (-vvv) to increase the level of detail.  [count]
  --browsertime.preURL, --preURL      A URL that will be accessed first by the browser before the URL that you wanna analyze. Use it to fill the cache.
  --browsertime.headless, --headless  Run the browser in headless mode. This is the browser internal headless mode, meaning you cannot collect visual metrics or in Chrome run any WebExtension.  [boolean] [default: false]
  --mobile                            Access pages as mobile a fake mobile device. Set UA and width/height. For Chrome it will use device Apple iPhone 6.  [boolean] [default: false]
  --resultBaseURL                     The base URL to the server serving the HTML result. In the format of
  --gzipHAR                           Compress the HAR files with GZIP.  [boolean] [default: false]
  --outputFolder                      The folder where the result will be stored.  [string]
  --firstParty                        A regex running against each request and categorize it as first vs third party URL. (ex: ".*sitespeed.*")
  --utc                               Use Coordinated Universal Time for timestamps  [boolean] [default: false]
  --config                            Path to JSON config file
  --help, -h                          Show help  [boolean]

Read the docs at

The basics

You can analyse a site either by crawling or by feeding with a list of URLs you want to analyse.

Analyse by URLs

The simplest way to run is to give it a URL:

docker run --shm-size=1g --rm -v "$(pwd)":/ sitespeedio/

If you want to test multiple URLs, just feed them:

docker run --shm-size=1g --rm -v "$(pwd)":/ sitespeedio/

You can also use a plain text file with one URL on each line. Create a file called urls.txt:

Another feature of the plain text file is you can add aliases to the urls.txt file after each URL. To do this, add a non-spaced string after each URL that you would like to alias: Start_page Important_Page We_are

Note: Spaces are used to delimit between the URL and the alias, which is why the alias cannot contain one.

Aliases are great in combination with sending metrics to a TSDB (such as Graphite) for shortening the key sent, to make them more user friendly and readable.

And run it:

docker run --shm-size=1g --rm -v "$(pwd)":/ sitespeedio/ urls.txt

Analyse by crawling

If you want to find pages that are not so performant it’s a good idea to crawl. will start with the URL and fetch all links on that page and continue to dig deeper into the site structure. You can choose how deep to crawl (1=only one page, 2=include links from first page, etc.):

docker run --shm-size=1g --rm -v "$(pwd)":/ sitespeedio/ -d 2

How many runs per URL?

When collecting timing metrics, it’s good to test the URL more than one time (default is three times). You can configure how many runs like this (five runs):

docker run --shm-size=1g --rm -v "$(pwd)":/ sitespeedio/ -n 5

Choose browser

Choose which browser to use (default is Chrome):

docker run --shm-size=1g --rm -v "$(pwd)":/ sitespeedio/ -b firefox


You should throttle the connection when you are fetching metrics. We have a special section on how you emulate connectivity for real users.

Viewport/user agent and mobile

You can set the viewport & user agent, so you can fake testing a site as a mobile device.

The simplest way is to just add --mobile as a parameter. The viewport will be set to 360x640 and the user agent will be Iphone6. If you use Chrome it will use the preset Apple iPhone 6 device.

docker run --shm-size=1g --rm -v "$(pwd)":/ sitespeedio/ --mobile

You can also set a specific viewport and user agent:

docker run --shm-size=1g --rm -v "$(pwd)":/ sitespeedio/ --browsertime.viewPort 400x400 --browsertime.userAgent "UCWEB/2.0 (MIDP-2.0; U; Adr 4.4.4; en-US; XT1022) U2/1.0.0 UCBrowser/ U2/1.0.0 Mobile"

Mobile testing is always best on actual mobile devices. You can test on Android phones using

Visual metrics and video

In 4.1 we released support for recording a video of the browser screen and use that to calculate visual metrics like Speed Index. This is one of the main benefits for using our Docker images, as it makes for an easy setup. Without Docker, you would need to install all the dependencies.

In 6.0 video and Visual Metrics is turned on by default, and if you want to turn them off you do like this:

docker run --shm-size=1g --rm -v "$(pwd)":/ sitespeedio/ --visualMetrics false
docker run --shm-size=1g --rm -v "$(pwd)":/ sitespeedio/ --visualMetrics false --video false

First party vs third party

You can categorise requests as first or third parties by adding a regexp. You will then get the size & requests by type both in HTML and sent to Graphite.

docker run --shm-size=1g --rm -v "$(pwd)":/ sitespeedio/ --firstParty ""

Output folder or where to store the result

You can change where you want the data to be stored by setting the --outputFolder parameter. That is good in scenarios where you want to change the default behaviour and put the output in a specific location:

docker run --shm-size=1g --rm -v "$(pwd)":/ sitespeedio/ --outputFolder /my/folder ""

Configuration as JSON

You can keep all your configuration in a JSON file and then pass it on to, and override with CLI parameters.

Create a config file and call it config.json:

  "browsertime": {
    "iterations": 5,
    "browser": "chrome"
  "graphite": {
    "host": "",
    "namespace": "sitespeed_io.desktopFirstView"
  "plugins": {
    "disable": ["html"]
  "utc": true

Then, run it like this:

docker run --shm-size=1g --rm -v "$(pwd)":/ sitespeedio/ --config config.json

If you want to override and run the same configuration but using Firefox, you just override with the CLI parameter:

docker run --shm-size=1g --rm -v "$(pwd)":/ sitespeedio/ --config config.json -b firefox

The CLI will always override the JSON config.



You can send the result of a run to Slack. First, set up a webhook in the Slack API ( and then configure it:

docker run --shm-size=1g --rm -v "$(pwd)":/ sitespeedio/ --slack.hookUrl

You can choose to send just a summary (the summary for all runs), individual runs (with URL), only errors, or everything, by choosing the respective slack.type.

docker run --shm-size=1g --rm -v "$(pwd)":/ sitespeedio/ --slack.hookUrl --slack.type summary


Log in the user

We have added a special section for that!