How it works
Once a day, we run Google Lighthouse on your site through the PageSpeed Insights API. You get four scores from 0 to 100: Performance, Accessibility, Best practices and SEO. The report also lists the biggest opportunities to speed up the page and the audits that failed in each category.
We test your monitored URL and, by default, 2 key pages picked from your sitemap. The lowest score of all pages sets the status. A score that drops by 10 points or more since the previous run warns you even while it is still green, so a deploy that slows the site down does not go unnoticed. The score history is charted over 30 days.
Settings
| Setting | Default | What it does |
|---|---|---|
| Warning score | 90 |
Warn when a score is below this. |
| Failure score | 50 |
Fail when a score is below this. |
| Strategy | mobile |
Test as a phone (mobile), a desktop (desktop), or both. |
| Key pages | 2 |
Extra pages from your sitemap to test. |
Statuses
| Status | Meaning |
|---|---|
| OK | Every score is at or above the warning score. |
| Warning | A score is below the warning score, a score dropped by 10 points or more, or Lighthouse could not run. |
| Failed | A score is below the failure score. |
By default you are notified of failures only.
Fixing common problems
- Low performance score: start with the opportunities listed in the report. They are sorted by the time they would save. Common fixes are compressing and resizing images, deferring scripts, and removing unused CSS and JavaScript.
- Low accessibility score: the failed audits name the elements to fix, such as missing image alt text, low colour contrast or form fields without labels.
- Scores vary between runs: Lighthouse runs on shared machines, so scores move by a few points. Lower the warning score a little if small changes alert you.