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Access the Web Performance Timeline, from your browser, in your terminal!

Browsertime allows you to:

A simple example

$ bin/browsertime.js

Load in Chrome three times. Results are stored in a json file (browsertime.json) with the timing data, and a har file (browsertime.har) in browsertime-results/$date/

I want more examples

Checkout the examples.


Supported Browsers

  • Chrome (desktop)
  • Firefox (desktop)
  • Android Chrome (mobile)

Future Support

  • Opera (desktop & mobile) - See:
  • Safari (desktop) - Waiting on Safari 10
  • iOS Safari (mobile) - Waiting on WebDriver support

How does it work

Browsertime uses Selenium NodeJS to drive the browser. It starts the browser, load a URL, executes configurable Javascripts to collect metrics, collect a HAR file.

To get the HAR from Firefox we use the HAR Export Trigger and Chrome we parse the timeline log and generates the HAR file.

Oh and you can run your own Selenium script before (--preScript) and after (--postScript) a URL is accessed, so you can login/logout or do whatever you want.

The rewrite to 1.0

The master is to a large degree a re-write of the internal implementation, the cli interface, and the node API. It’s based on the learnings from the previous releases of Browsertime, and their use in It’s still lacking some features from the 0.x releases, and the API is not final. However it should be a better foundation for future development, using more modern Javascript features and a much more extensive test suite.

  • With 1.0 we’ve dropped BrowsermobProxy, so you don’t need Java to run it. This makes each run significantly faster. :smile:
  • We now support HTTP/2!
  • If you want to do things before or after the URL is tested we support pre and post selenium scripts.

If you would would like to get started there are a few examples that can be found in the docs folder. If you run into any issues getting started using Browsertime visit our issues page for some common issues/solutions. If you still cannot resolve the problem and feel the issue is within browsertime feel free to open an issue.