Website Change Monitor & Diff Checker

🔎 Find webpage changes without checking by hand

Webpage Diff Checker is for SEO teams, developers, and site owners who track public pages. It compares each page with its last good baseline and returns added or removed text, metadata and link changes, severity, and key page facts.

• Website change monitoring — check public pages again and see what changed.
• Webpage diff checking — compare visible text or HTML with the last good baseline.
• Competitor page monitoring — watch public product, feature, and news pages.
• SEO metadata change tracking — find changes to titles, descriptions, canonical links, hreflang, and robots rules.
• Structured data change monitoring — track JSON-LD, microdata, RDFa, and Open Graph changes.
• Website link change tracking — find internal and external links that were added or removed.
• Pricing page change monitoring — focus on price words or a CSS section.
• Policy page change monitoring — keep separate named baselines for terms and policy pages.

📦 Returned data

Each saved dataset row is one page that was fetched and checked. It includes:

• requested and final URL, check time, HTTP status, response time, redirect state, page size, and content fingerprint
• new, unchanged, or changed status
• a short summary, change magnitude, severity, and categories
• added and removed text, plus watched keywords found in the changes
• SEO and semantic metadata changes with before and after values
• internal and external links added or removed

The run summary also gives totals for checked, changed, new, unchanged, and failed pages. Failed pages include error details there. A failed fetch does not replace the last good baseline.

🚀 Running the Actor

1. Add one or more public HTTP or HTTPS webpage URLs.
2. Give the monitor a stable name so it keeps its own baselines.
3. Choose visible text or HTML. You can also pick a CSS section or content scope.
4. Add watched keywords or rules that remove known page noise if needed.
5. Choose all page rows or only new and changed pages. Failed checks stay in the run summary.
6. Run the Actor. Run the same setup again to compare with the saved baseline.

The first successful check for a page creates its baseline. Later successful checks compare with it and then save the new good baseline.

🧾 Input

urls is required. Public options also include monitorName, comparisonType, cssSelector, contentScope, watchedKeywords, excludedPageParts, excludedSelectors, excludedPatterns, proxyConfiguration, and resultMode.

{
  "urls": [
    { "url": "https://example.com/" },
    { "url": "https://www.iana.org/help/example-domains" }
  ],
  "monitorName": "public-pages",
  "comparisonType": "visibleText",
  "contentScope": "mainContent",
  "watchedKeywords": ["price", "policy"],
  "excludedPageParts": ["headers", "footers"],
  "resultMode": "changedOnly"
}

Use a different monitorName for each separate set of baselines. The Actor checks public pages only. It does not log in to private pages or make screenshot or pixel diffs.

📤 Output

A changed page row can look like this:

{
  "requestedUrl": "https://example.com/news",
  "finalUrl": "https://www.example.com/news",
  "status": "changed",
  "checkedAt": "2026-07-21T10:15:30.000Z",
  "httpStatus": 200,
  "responseTimeMs": 384,
  "redirected": true,
  "contentSizeBytes": 18420,
  "fingerprint": "sha256:2cf24dba5fb0a30e",
  "change": {
    "summary": "The page title changed and a pricing section was added.",
    "magnitude": 0.18,
    "severity": "medium",
    "categories": ["content", "seo"],
    "addedText": ["Plans start at $20."],
    "removedText": ["Contact us for pricing."],
    "watchedKeywords": ["price"]
  },
  "metadataChanges": [
    { "kind": "title", "name": "title", "before": "News", "after": "Product news" }
  ],
  "linkChanges": {
    "addedInternal": ["https://www.example.com/pricing"],
    "removedInternal": [],
    "addedExternal": [],
    "removedExternal": []
  }
}

Open the dataset for page rows. Open the output key-value store record for run totals and failure details.

💳 Pricing

This Actor uses pay-per-event pricing. One Page check event is charged for each webpage that is successfully fetched and checked for changes. Failed fetches and failure details do not create this event. Check the Pricing tab for current tier prices.

🔌 Integrations

Use Apify datasets, the API, schedules, webhooks, and platform integrations to run repeat checks and send the output to your workflow.

❓ FAQ

What happens on the first run?

The first successful check creates a new baseline. There is no older page content to compare yet.

What happens if a page fails to load?

The run summary lists the failure and its details. The Actor keeps the last good baseline, so a failed page does not become the next comparison source.

How can I avoid cookie banners and changing counters?

Common changing noise is cleaned on its own. You can also leave out common page parts, CSS selectors, or text matched by regex patterns.

Can I watch only one part of a page?

Yes. Add a cssSelector, or choose main content or article content as the content scope.

Can it check private pages or compare screenshots?

No. It checks public HTTP and HTTPS pages without a login. It compares visible text or HTML, not pixels or screenshots.

Can it find old versions from the Internet Archive?

No. It compares repeat checks made with this Actor. Use Wayback Machine Search when you need saved Internet Archive history.

Should I use one monitor name for every task?

Use one stable name for each monitor. Give separate tasks different names so their baselines do not replace one another.

📝 Changelog

• 0.0: Initial release.

🆘 Support

For issues, questions, or feature requests, file a ticket and I'll fix or implement it in less than 24h 🫡

🔗 Related Actors

• Webpage Text Extractor — extract clean text or Markdown from public pages.
• Website URL Crawler & Link Extractor — build the URL list for a site before you monitor chosen pages.
• Wayback Machine Search — find older page snapshots from the Internet Archive.
• Seobility SEO Checker — run a current on-page SEO audit alongside change tracking.
• Sitemap Sniffer — find public sitemap files and page URLs to check.

Made with ❤️ by Maxime Dupré