Website Change Tracker - Competitor & Price Monitoring

Track how any public webpage changes over time using the Wayback Machine CDX API — no browser automation, no proxies, and no blocked requests. Built for competitive intelligence teams, product managers, and SEO analysts who need a reliable, reproducible audit trail of a URL's content history.

What does Website Change Tracker do?

Website Change Tracker queries the Internet Archive's CDX API to retrieve a structured snapshot history for any URL. It detects content changes by comparing consecutive page digests (SHA-1 content hashes) — if two snapshots have different digest values, the page changed between those timestamps. This approach is lightweight, highly reliable, and works against any URL the Wayback Machine has indexed, including competitor pricing pages, landing pages, terms of service, and product listings.

The Actor operates entirely through the public CDX API and does not directly visit the target website. This means there are no IP blocks, no bot detection issues, and no CAPTCHAs — it reads what the Archive has already stored. Wayback Machine coverage varies by domain popularity and crawl frequency; well-known commercial sites are typically snapshotted multiple times per day.

Four analysis modes cover different use cases. Recent changes mode identifies all content changes within a configurable lookback window (1–3,650 days) along with the exact timestamps and direct links to archived versions. Full history mode returns a year-month breakdown of the entire snapshot archive. Compare mode produces a side-by-side diff metadata summary between two specific dates. Change frequency mode analyzes how often the page changes and trends over time.

Key features

• Digest-based change detection — uses SHA-1 content hashes from CDX records to identify genuine content changes, not just recrawls
• 4 analysis modes — recent changes, full history, compare dates, and change frequency
• Direct Wayback links — each detected change includes a direct URL to the archived snapshot for manual inspection
• Configurable lookback — recent changes mode supports 1 day to 10 years of lookback window
• Year-month timeline — full history mode groups snapshots by year and month with unique version counts
• Date comparison — compare mode fetches nearest snapshots to two specified dates for before/after review
• Change frequency analysis — calculates average days between changes and total unique content versions
• No target site access — reads exclusively from Wayback Machine CDX API; the target site is never contacted
• Snapshot limit control — configure how many CDX records to retrieve (1–500) for cost and speed tradeoffs
• Pay-per-event pricing — charged only when analysis completes successfully

Use cases

• Competitive intelligence analysts: Monitor competitor pricing pages and product listings for changes week-over-week without manual checking
• Product managers: Track when a competitor launches a new feature or updates their homepage messaging
• Legal and compliance teams: Maintain an audit trail of how a company's terms of service, privacy policy, or regulatory disclosures changed over time
• SEO professionals: Monitor changes to competitor landing pages, metadata, and content structure to inform content strategy
• Due diligence researchers: Verify whether a company's website claims have changed before or after a specific event (funding round, acquisition, regulatory action)
• Journalists and investigators: Document the history of a website's claims or content as time-stamped, archived evidence

How to use Website Change Tracker

1. Configure input — Provide the full URL to track (e.g., https://stripe.com/pricing), select a mode, and set the lookback period in days for recent changes mode or specify two dates for compare mode. Adjust the snapshot limit to control how many CDX records are analyzed.
2. Run the Actor — Click "Start" in Apify Console or call via the Apify API
3. Get structured results — Output is pushed to the Apify dataset as structured JSON with change timestamps and Wayback links

Input parameters

Parameter	Type	Required	Default	Description
url	string	Yes	https://example.com	Full URL of the page to analyze
mode	string	No	recent_changes	Analysis mode: recent_changes, full_history, compare, or change_frequency
days	integer	No	30	Lookback period in days for recent_changes mode (1–3,650)
compareDate1	string	No	—	First date for compare mode (format: YYYY-MM-DD). Required for compare mode
compareDate2	string	No	—	Second date for compare mode (format: YYYY-MM-DD). Defaults to today if omitted
limit	integer	No	50	Maximum number of Wayback Machine snapshots to retrieve (1–500)

Output example

{
  "mode": "recent_changes",
  "url": "https://stripe.com/pricing",
  "days": 30,
  "total_snapshots": 24,
  "change_count": 4,
  "changes": [
    {
      "changed_at": "2026-03-12T14:22:05Z",
      "prev_timestamp": "2026-03-09T08:11:42Z",
      "days_since_prev": 3,
      "new_length": 89241,
      "status_code": "200",
      "wayback_url": "https://web.archive.org/web/20260312142205/https://stripe.com/pricing"
    },
    {
      "changed_at": "2026-03-05T21:44:18Z",
      "prev_timestamp": "2026-03-01T10:30:00Z",
      "days_since_prev": 4,
      "new_length": 87904,
      "status_code": "200",
      "wayback_url": "https://web.archive.org/web/20260305214418/https://stripe.com/pricing"
    }
  ],
  "last_changed": "2026-03-12T14:22:05Z",
  "change_frequency": "~every 7 days",
  "summary": "4 change(s) detected for https://stripe.com/pricing in the last 30 days. Changes approximately ~every 7 days.",
  "timestamp": "2026-03-21T10:00:00.000Z"
}

Full history output example

{
  "mode": "full_history",
  "url": "https://stripe.com/pricing",
  "total_snapshots": 312,
  "first_seen": "2012-04-14T09:00:00Z",
  "last_seen": "2026-03-20T18:30:00Z",
  "years_tracked": 14,
  "unique_versions": 87,
  "by_year": [
    { "year": "2024", "snapshot_count": 48, "months_active": 12 },
    { "year": "2025", "snapshot_count": 52, "months_active": 12 }
  ],
  "summary": "https://stripe.com/pricing has 312 snapshot(s) spanning 14 year(s). 87 unique content version(s) detected."
}

Pricing

Each successful analysis costs $0.05 under Apify's pay-per-event model. You only pay when the result is successfully pushed to the dataset. Failed runs are not charged. Learn more about pay-per-event pricing.

API and integrations

Call this Actor via the Apify API, schedule weekly runs for ongoing competitor monitoring, or connect results to Slack, Google Sheets, or Airtable via Zapier or Make to receive change alerts automatically. Results are available as JSON, CSV, or Excel from the Apify dataset.

Limitations

• Coverage depends entirely on what the Wayback Machine has indexed. Low-traffic or recently launched sites may have sparse or no snapshot history.
• Change detection is based on full-page content digest comparison. Cosmetic changes (CSS, image updates) and structural changes to text are both detected equally — there is no diff of the text content itself, only detection that a change occurred.
• The CDX API may return HTTP 429 rate limit errors during periods of high Wayback Machine load. The Actor includes automatic retry logic, but very large limit values may occasionally time out.