Logo with My Little Pony style cats

Welcome to the wonderful world of Web Performance is a set of Open Source tools that makes it easy to monitor and measure the performance of your web site.

Measuring performance shouldn’t be hard: you should be able to have full control of your metrics, own your own data and you should be able to do it without paying top dollars.

That’s why we created


Use our Docker container to get an environment with Firefox, Chrome, XVFB and up and running as fast as you can download them. They work extremely well together with Graphite/InfluxDB and Grafana.

docker run --rm -v "$(pwd)":/ sitespeedio/

If you want to test a user scenario/journey read how to run test scripts.


Install globally:

npm install -g

And then run:

Follow our connectivity guide to emulate real users connectivity. 9.0

Stop what you are doing and try out the new 9.0! It will blow your mind :) You get a lot of more insights of where your page spends the CPU time and we also makes it easier to pinpoint 3rd party problems. Read the blog post to find out more.

What tool should I use?

The power of - Pippi Longstocking logo

If you want to measure the performance and are only interested in timing metrics, you should focus on using Browsertime. If you want it all: use It is the main tool that uses all tools and add supports for testing multiple pages as well as adds the ability to report the metrics to a TSDB (Graphite and InfluxDB).

If you are a performance tool maker you should look at The coach, Browsertime, Chrome-HAR, PageXray and Throttle. They can all help you depending on what you are building.

We believe in privacy

We take your privacy really serious: Our documentation site, our dashboard and our compare tool do not use any tracking software at all (no Google Analytics or any other tracking software). None of the tools call home.

But beware: Chrome and Firefox can call home (we know for fact that they both do). We would love PRs and tips how to make sure browsers don’t call home when you run your tests.

Read more about how we do things.

What does it cost? Public Enemy logo is Open Source and totally free. But what does it cost to have an instance of up and running?

If you don’t run on your own servers, we recommend running on Digital Ocean optimized droplets 2 vCPUs or on AWS c5.large, storing the data at S3. On one instance you can run something like 80000+ runs per month for a total cost of $695 per year.

Look more into the details here.

Browsertime 5.0

Browsertime logo

Browsertime 5.0 supports testing multiple pages within the same browser session and scriptinmg. You should use Browsertime if you want a raw JSON result for timings and/or execute your own JavaScript. Browsertime is perfect if you wanna build your own performance tool, as VoxMedia did when they created Lightbike built on top of Browsertime.

Thank you! is built upon Open Source tools, we have a special place in our hearts for those projects (see the full list):


There’s a lot of things you can do to help us make even better than it is today.

If you code, write documentation or do UX you can check the help section and the full issue list.

These people has already improved with pull requests or ideas (massive love!).