Website Change Monitor | Page Diff Alerts

Competitive intelligence, product operations, and web teams use this Actor to track approved public pages. Input public URLs with optional CSS focus and noise filters. Get source-linked added/removed text, change alerts, snapshots, and portfolio digest reports.

Store Quickstart

The first run stores a free baseline. Schedule the same input to receive rows only when the watched content changes.

{
  "targets": [
    {
      "name": "Competitor pricing",
      "url": "https://example.com/pricing",
      "cssSelector": "main",
      "ignoreSelectors": [".cookie-banner"]
    }
  ],
  "initialRunMode": "baseline_only",
  "generateDigest": true,
  "emitSnapshots": false,
  "emitUnchanged": false,
  "maxDiffSegments": 20,
  "maxChargeUsd": 10,
  "snapshotKey": "competitor-pricing",
  "dryRun": false
}

An unchanged run writes zero dataset rows and creates zero event charges.

Run the next report

• Audit content, headings, metadata, and crawlability with Site QA Content Report.
• Compare pricing, changelogs, release notes, and status pages with SaaS Pricing & Changelog Battlecard.
• Run a multi-site technical regression audit with Technical SEO & AI Crawler Audit.

Input examples

Pricing-page watch

{
  "targets": [
    {
      "name": "Pricing",
      "url": "https://example.com/pricing",
      "cssSelector": "main",
      "ignoreSelectors": [".last-updated"]
    }
  ],
  "initialRunMode": "baseline_only",
  "stripDates": true,
  "generateDigest": true,
  "maxChargeUsd": 10,
  "snapshotKey": "pricing-watch",
  "dryRun": false
}

Product documentation watch

{
  "targets": [
    {
      "name": "API changelog",
      "url": "https://example.com/changelog",
      "cssSelector": "article",
      "ignoreSelectors": []
    },
    {
      "name": "API limits",
      "url": "https://example.com/docs/limits",
      "cssSelector": "main",
      "ignoreSelectors": ["nav"]
    }
  ],
  "initialRunMode": "baseline_only",
  "stripDates": false,
  "stripVolatileNumbers": false,
  "generateDigest": true,
  "maxDiffSegments": 30,
  "maxChargeUsd": 10,
  "snapshotKey": "api-docs-watch",
  "dryRun": false
}

Paid first-observation trial

Use emit_backfill only when you explicitly want the current page captured as the first change row.

{
  "targets": [
    {
      "name": "Terms page",
      "url": "https://example.com/terms",
      "cssSelector": "main",
      "ignoreSelectors": []
    }
  ],
  "initialRunMode": "emit_backfill",
  "generateDigest": false,
  "emitSnapshots": false,
  "maxChargeUsd": 0.1,
  "snapshotKey": "terms-trial",
  "dryRun": false
}

Sample output

{
  "rowType": "url_change",
  "billingEventName": "url-change-detected",
  "targetName": "Competitor pricing",
  "sourceUrl": "https://example.com/pricing",
  "changeKind": "content_hash_diff",
  "addedSegments": ["The Pro plan now includes priority support."],
  "removedSegments": ["The Pro plan includes standard support."],
  "addedSegmentCount": 1,
  "removedSegmentCount": 1,
  "changeRatio": 0.25,
  "contentHash": "bcf38e4a58839f6c7686c3f1",
  "previousContentHash": "dba4a91988d5ed0d5f3dbd31",
  "checkedAt": "2026-07-27T01:00:00.000Z"
}

Each change row includes the source URL, final URL, HTTP status, current and previous hashes, bounded added/removed text segments, a change ratio, and a stable key. Digest rows summarize all changed targets in the run.

Pricing

Event	Price	Delivered when
url-change-detected	$0.08	A normalized watched region changes, or an explicit backfill is requested
url-snapshot	$0.02	emitSnapshots is enabled and a public page is fetched successfully
change-digest-report	$5.00	At least one change exists and generateDigest is enabled

maxChargeUsd is checked before delivery. The Actor fails before pushing billable rows if the configured output would exceed the buyer-approved cap.

Change controls

• cssSelector limits the watched region to a simple ID, class, or tag selector.
• ignoreSelectors removes known noisy regions.
• stripDates removes common timestamps before hashing.
• stripVolatileNumbers normalizes long counters.
• maxDiffSegments bounds the added and removed text included in each row.
• snapshotKey keeps recurring watches isolated.

Compliance and limitations

• Public HTTP(S) pages supplied by the buyer only.
• Private networks, metadata endpoints, non-HTTP URLs, disallowed robots paths, access challenges, and login walls fail closed.
• Redirect count, response size, and request time are bounded.
• Results are source-linked observations and do not determine legal, security, compliance, or financial conclusions.
• Lightweight CSS focus is not a full browser selector engine, and text diffs do not represent pixel-level layout changes.

See also

• Site QA Content Report
• SaaS Pricing & Changelog Battlecard
• Technical SEO & AI Crawler Audit