Updated 25 October 2026 · By the Upcertain team
The failures status codes miss
- A framework renders its error page with status 200.
- A CDN serves a cached copy of a maintenance page.
- The product list loads but is empty because the search index is down.
- A login page renders, but the form posts to a broken endpoint, so the success text never appears.
- A health endpoint answers 200 with
"database":"down"inside.
How it works
A keyword monitor requests the URL like an HTTP monitor and then searches the response for a word or phrase of up to 500 characters. Must contain fails when the phrase is missing; must not contain fails when it appears. Matching ignores case unless you turn case-sensitive matching on. The first 1 MB of the response is searched.
Good keywords
| Page | Mode | Keyword |
|---|---|---|
| Shop category | Must contain | Add to basket |
| Checkout | Must contain | Order summary |
| Any page | Must not contain | Something went wrong |
| JSON health check | Must contain | "status":"ok" |
| Status of a dependency | Must not contain | "database":"down" |
Pick text that appears only when the page works. Your company name is a poor keyword: it is on the error page too.
Alerts that say why
When a keyword check fails, the incident and every alert name the cause, Keyword missing or Keyword present, so whoever picks it up knows the server answered and the content is wrong. Keyword monitors have the same intervals, confirmation checks and alert channels as every other monitor.
Limits to know
The search reads the HTML the server sends, before any JavaScript runs. For pages rendered in the browser, monitor a server-rendered page or an API response that carries the same information. Upcertain does not run a browser.
Questions
Can a keyword monitor check JSON?
"status":"ok" works on a JSON health endpoint. Include the quotes so the match is exact.