Monitoring a page
Intervals, sensitivity, selectors — the three settings that decide how often you hear from Detector.
Every monitored page has three settings. Most pages only ever need the first two.
Check interval
How often the page is fetched. Shorter intervals cost more credits and rarely change the answer: a supplier's terms page checked hourly and checked daily give you the same notification, a few hours apart.
Pick the interval from how quickly you would need to act, not from how often the page might move.
Sensitivity
How much of the page has to move before you are told, as a share of the page's text weighted by block. Three settings cover almost everything:
- Low — only substantial edits. Good for long pages with active footers.
- Normal — the default. A rewritten paragraph or a changed price triggers.
- High — any edit outside the filtered regions, including single words.
Start at Normal. If you get a notification you did not care about, the fix is usually a selector rather than a lower sensitivity.
Selectors
A CSS selector narrows the comparison to one region of the page:
#pricing-table
main article
[data-testid="terms-body"]
Everything outside the selector is ignored entirely, which is both the point and the risk — if the site restructures and the selector stops matching, the check fails loudly rather than silently reporting no changes.
When a check fails
A page that returns a non-2xx status, times out, or no longer matches its selector is marked failing and retried on the next interval. After three consecutive failures you get one notification and the page is paused, so a site that has gone away does not spend the rest of the month's credits.