How do speed alerts work?

Speed alerts is a card on Web SEO → Page speed in each project.

How a page is judged

SEOmise already tests your most visited pages every week, and again after a page changes. Each page is compared with its own usual speed: the middle value (median) of its five earlier tests. A page is reported only when it was slower on its two newest tests in a row, because one lab test can be slow by chance:

• the speed score fell by 10 points or more;
• the main content (Largest Contentful Paint) showed 500 ms and 20% later or more;
• the layout shift (Cumulative Layout Shift) rose by 0.05 or more;
• reactions to taps and clicks (Interaction to Next Paint) slowed by 100 ms or more, only when Google's field data from real visitors comes with the test.

Phone tests are watched; staff can add computer tests. A page needs at least three earlier tests before it is compared.

What changed

Where the data allows, the alert says what changed between the usual tests and the slow ones: the page itself changed, the server answered more slowly, scripts kept the page busy for longer, Google's test tool changed version, or changes were published from SEOmise in between.

Messages

People who manage the project get one message per check (bell and e-mail, as each person chose in their notification settings), listing up to ten pages. A site-wide slow-down raises at most ten new alerts at a time. A page is not reported again within 14 days. Dismiss closes an alert and keeps that page quiet for the same time; a page that is fast again closes as Fast again.

Every platform

The check reads Google's tests, so it works for any website. Speed fixes has the fixes for your platform: applied through the site connector, or as steps to follow by hand, then checked by the next test.

Staff set every threshold under Settings → Policies → Speed alerts.