Website Change Monitor — see the actual diff, not just a ping

Put it on a schedule with your list of URLs. Every run, each page is fetched, fingerprinted, and compared with the previous run — and when something changes you get the changed lines themselves (diffAdded / diffRemoved), not a useless "something changed" flag.

What it catches

• Edits — price changes, doc updates, policy rewrites, changelog entries
• Removals — content quietly deleted from a page
• Pages going dark — a previously-live page returning 404/410 (status: "gone")

Typical uses

Competitor pricing pages, terms-of-service watching, job boards, product docs, government/regulatory pages, "is my own site still up and unchanged" sanity checks.

Statuses

status	meaning	billed?
baseline	first time this URL is seen — fingerprint stored	yes
unchanged	same content as last run	yes
changed	content differs — see diffAdded/diffRemoved	yes
gone	a previously-observed page now returns 404/410	yes
restored	page back online after gone	yes
not-found	404/410 on a URL we never successfully saw (typo?)	no
fetch-error	timeout / 5xx / blocks / non-text content	no — never

You pay per verdict, not per attempt. If we can't reach a page, that row is free and the old baseline is kept so the next run diffs correctly.

Honest limits

• Monitoring scope is the first 2,000 text lines (300 chars each) of a page — the same capped content is fingerprinted, stored, and diffed, so verdicts and diffs always agree. Virtually every real page fits.
• Bot-protected sites may block cloud IPs. Blocks show up as free fetch-error rows; switch on the RESIDENTIAL proxy input for those targets.
• Up to 500 URLs per run (duplicates removed); split bigger sets across schedules with different stateKeys.
• No JavaScript rendering. Server-rendered HTML only. Heavy SPAs that draw everything client-side will show little text (check textLength); this tool is the wrong fit for those — and we'd rather say so than bill you for noise.
• sectionHint is a plain-text region anchor (id/class/heading), deliberately simpler than CSS selectors — it cuts header/footer noise on most real pages.
• Fingerprints normalize whitespace, so cosmetic reformatting won't false-alarm, but a rotating timestamp printed in page text will. Use sectionHint to scope.

Suggested setup

1. Create a Schedule (hourly/daily) with your URL list as input
2. Add an Apify webhook on run-succeeded → Slack/Discord/email/Zapier
3. Filter rows where status = "changed" or "gone"

Built by the maker of the whale-tracking and MCP suite — same rules everywhere: fail-loud integrity, errors never billed, state committed only after your data is safely delivered.