Website Change Monitor

Watch any list of web pages and get a clear report of exactly what changed since the last check — added text, removed text, or nothing. Schedule it and never manually re-check a page again.

What people monitor

• Competitor pricing pages — know the day they change a price
• Job boards & career pages — new postings the moment they appear
• Terms of service / policy pages — get an audit trail of every revision
• Product pages — stock status, spec changes
• Government & permit pages — tenders, filings, announcements

How it works

1. First run saves a baseline snapshot of each page (status: "first_snapshot")
2. Every later run compares each page against its stored snapshot and reports changed, unchanged, or unreachable
3. Changed pages include a readable diff: how many lines were added/removed, with samples of each — so you can see what changed without opening the page

Snapshots persist between runs in a named key-value store, so this Actor is built to be scheduled (daily and weekly are the common choices).

Killing false alarms

Change monitors live or die on noise control:

• CSS selector — watch only the part of the page that matters (#price, .job-listings, main). Rotating banners and footers stop triggering alerts.
• Ignore numbers — masks all numbers before comparing, so view counters, dates, and visitor stats don't count as changes (price watchers: leave this OFF).
• Whitespace and layout-only changes are normalized away automatically; scripts and styles are ignored.

Input example

{
    "startUrls": [{ "url": "https://competitor.com/pricing" }],
    "cssSelector": "main",
    "ignoreNumbers": false
}

Output example

{
    "url": "https://competitor.com/pricing",
    "checkedAt": "2026-08-26T09:00:12.000Z",
    "status": "changed",
    "previousSnapshotAt": "2026-08-25T09:00:09.000Z",
    "linesAdded": 1,
    "linesRemoved": 1,
    "addedSamples": ["Pro plan – $59/month"],
    "removedSamples": ["Pro plan – $49/month"]
}

Results are sorted with changed pages first. A SUMMARY record (counts of changed/unchanged/unreachable) is saved to the run's key-value store, and the run's status message reads like "2 of 15 page(s) CHANGED" so scheduled-run notifications are informative at a glance.

Getting notified

Use Apify's built-in integrations on this Actor (Integrations tab → add):

• Email or Slack on run finished — the status message tells you immediately whether anything changed
• Webhook to pipe changed results anywhere else

Scheduling (the point of this Actor)

Console → this Actor → Schedules → e.g. every day at 9:00. Each scheduled run compares against the previous one. That's the whole setup.

Tips

• The first run of any URL always reports first_snapshot — that's the baseline, not a bug.
• If you change the CSS selector or the "ignore numbers" setting, expect one round of changed reports as new baselines are established.
• resetSnapshots: true wipes the slate and re-baselines everything.
• Some sites block automated traffic (status: "unreachable"); enabling Apify Proxy in the input usually fixes it.

Pricing

Pay-per-result: billed per page check (one output row per URL per run). Monitoring 20 pages daily costs roughly a dollar a month.