Site Speed Sentinel
Measures your site every night and shouts when it gets slower.
What you're making
Sites get slower one commit at a time and nobody notices until it's bad. This measures yours every night, keeps the history, and tells you when a page gets meaningfully slower — with the date, so you can find what caused it. It only complains about real regressions, not the normal noise between runs.
A scheduled performance audit that records metrics over time and alerts on regression. Separating a genuine regression from run-to-run variance is the entire judgement call.
Hosting · Free forever
Deploys free on GitHub Actions, Cloudflare Workers Cron or your own machine.
GitHub Actions runs scheduled jobs free on public repositories, so this can tick along without a server.
Runs on a schedule for free, or on your own machine.
Core features · 7
- Audits a list of pages on a nightly schedule
- Records core performance metrics over time
- Charts each metric's history
- Alerts only when a change exceeds normal variance
- Runs several samples per page and takes the median
- Reports which metric regressed and by how much
- Runs free on scheduled CI
The interesting part
- Performance numbers are noisy — a single run tells you almost nothing
- Choosing a threshold that catches real regressions without crying wolf
- Keeping history somewhere durable when the job has no database
Once it works
- Compare against a competitor's site
- Correlate regressions with deploys
- Add a budget that fails the build