sitespeed.io

sitespeed.io is an open source tool that tests the web performance of a page or a scripted user journey in Chrome, Firefox, Edge or Safari, including Chrome on Android and Safari on iOS. Each run produces an HTML report with Core Web Vitals, a video and filmstrip of the page loading, the HAR waterfall, CPU main-thread timings and recommendations from its Coach component.

Connection throttling can simulate mobile networks. Run on a schedule, it sends its metrics to Graphite or InfluxDB, and the project supplies a Docker Compose setup with ready-made Grafana dashboards to track performance over time.

The project dates from 2012 and is published under the MIT licence. It runs from Docker or npm and is built from separate packages (Browsertime, Coach, PageXray, Throttle) that can also be used on their own. It sends no data back to the project.