How to contribute

Sitespeed.io continues to evolve thanks to people who contributes, so please please help out. Check our list of what you can do to help us.

Making changes

If you want help out, that's great! Before taking the time to code something big, feel free to open an issue first proposing your idea to other contributors, that way you can get feedback on the idea before taking time to write precious code.

AI-Assisted Contributions

When using AI tools like Claude, ChatGPT, or any other LLM to assist with development, please disclose it in your commits and in the pull request description.

Commits

Add a Co-authored-by: trailer to the commit message body naming the model. GitHub recognises the trailer and credits the model alongside the human author, which keeps the disclosure visible on every commit page without relying on a custom convention. Use a sensible model identifier in the name part and the vendor's published noreply address. Multiple Co-authored-by: lines are allowed if more than one model contributed.

Example:

Add Cumulative Layout Shift metric to the summary page

Add the Cumulative Layout Shift (CLS) introduced by Google on
the summary page. Show both median and p75.

Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

Pull Requests

When creating a pull request that includes AI-assisted work, please mention it in the pull request description.

Example:

This pull request implements Cumulative Layout Shift with assistance from Claude.

Add a defect

Please make sure you run the latest version of sitespeed.io. Then check the defect/bug list to make sure that it hasn't been filed yet.

If you find a defect, please file a bug report. Include the following:

• Explain the bug/defect and what you where doing.
• OS & versions
• Always add the URL of the page you where analysing (if it is secret, drop me an email peteratsoulgalore.com and send me the address).
• Add a screenshot and clearly point out where the defect is (if applicable)
• Include the content of the sitespeed.io.log file in a gist and attach it to the issue.

If you have the skills & the time, it is perfect if you send a pull request with a fix, that helps us a lot!

Add a change request/new functionality request

If you have an idea or something that you need sitespeed.io to handle, add an issue and lets discuss it there. Ideas/changes/requests are very very welcome!

Thanks for your time & support!

Peter