What is Sitespeed.io used for?

sitespeed.io tests and monitors website speed using real browsers and reports Core Web Vitals; it is open source and runs on your own infrastructure. It is a good fit for detecting web performance regressions in CI, monitoring site speed over time and debugging slow pages.

Is Sitespeed.io open source?

Yes. Sitespeed.io is open source under the MIT licence. Its source code is on GitHub at sitespeedio/sitespeed.io and is written mainly in JavaScript.

Is Sitespeed.io free?

Yes. Sitespeed.io is open source, so the software itself is free to use.

What is Sitespeed.io an alternative to?

Sitespeed.io is an open-source alternative to Pingdom, Checkly, Catchpoint and Dotcom-Monitor. Other open-source alternatives to Pingdom include OpenStatus, OneUptime and Uptime Kuma.

Is Sitespeed.io actively maintained?

Yes. The most recent commit to Sitespeed.io was on 30 September 2026, and the latest release is v42.7.0, published on 11 September 2026. The project has 5k stars on GitHub.

Sitespeed.io: open-source alternative to Pingdom, Checkly

About Sitespeed.io

sitespeed.io is open-source software for measuring web performance. You run it against a page or a set of pages, and it drives real browsers to measure how fast they load, producing an HTML report that includes Core Web Vitals and a video recording, so you can debug a slow page or compare changes over time.

It can be installed with Docker or Node.js, supports basic and advanced configuration, and includes guidance for mobile testing. Teams run it from CI or on a schedule to monitor performance continuously and catch regressions. The repository lists metrics, performance analysis and dashboards among its topics, and the project is active on Bluesky and Mastodon with a public changelog.

sitespeed.io is written in JavaScript and licensed under MIT. It runs on your own machines or servers, so no hosted account is needed. It suits front-end developers, performance engineers and operations teams that want self-controlled performance budgets and monitoring.

Key features

Real browser performance testing
HTML reports with Core Web Vitals
Video recordings of page loads
Docker and Node.js installation
Mobile testing support
Continuous monitoring from CI or schedules

Good fit for

→Detecting web performance regressions in CI
→Monitoring site speed over time
→Debugging slow pages

Built with: JavaScript
Tags: web-performance; monitoring; core-web-vitals; webperf; docker; performance-testing; javascript

Sitespeed.io: questions and answers

What is Sitespeed.io used for?: sitespeed.io tests and monitors website speed using real browsers and reports Core Web Vitals; it is open source and runs on your own infrastructure. It is a good fit for detecting web performance regressions in CI, monitoring site speed over time and debugging slow pages.
Is Sitespeed.io open source?: Yes. Sitespeed.io is open source under the MIT licence. Its source code is on GitHub at sitespeedio/sitespeed.io and is written mainly in JavaScript.
Is Sitespeed.io free?: Yes. Sitespeed.io is open source, so the software itself is free to use.
What is Sitespeed.io an alternative to?: Sitespeed.io is an open-source alternative to Pingdom, Checkly, Catchpoint and Dotcom-Monitor. Other open-source alternatives to Pingdom include OpenStatus, OneUptime and Uptime Kuma.
Is Sitespeed.io actively maintained?: Yes. The most recent commit to Sitespeed.io was on 30 September 2026, and the latest release is v42.7.0, published on 11 September 2026. The project has 5k stars on GitHub.