WebCheck does not currently alert on every change to a page. Its content checks look for a specific phrase that you require or forbid in the HTTP response.
What content checks can do
A required-text check fails when its configured phrase is missing. A forbidden-text check fails when that phrase is present. Matching is an exact, case-sensitive substring search in the response body WebCheck receives.
WebCheck records a response hash as run evidence, but it does not compare that hash with a saved baseline or raise an alert for any arbitrary page change.
Required and forbidden text
Use a heading or service message that should remain present, or a known error message that should stay absent. Avoid phrases containing timestamps, prices, rotating offers, personalised content or other values that change normally.
When a whole-page content diff is needed
Use a tool designed to compare rendered pages or response snapshots if you need to detect arbitrary changes. WebCheck's text assertions are narrower: they answer whether the configured phrase appeared in the response for that run.