Pricing

from $5.00 / 1,000 url checkeds

Semantic Change Detector

Monitor web pages for meaningful content changes, ignoring noisy timestamps and counters. Optional webhook alerts on change. $0.005/URL + $0.02 start.

Pricing

from $5.00 / 1,000 url checkeds

Rating

0.0

(0)

Developer

ando

Actor stats

Bookmarked

Total users

Monthly active users

4 days ago

Last modified

Features

Two sensitivity modes — meaningful (ignores timestamps/counters) or any (raw text diff)
CSS selector scoping — check only the part of the page you care about (e.g. a pricing table or article body)
Persistent snapshots — stores the last-seen state per URL in a named key-value store (semantic-change-snapshots), so subsequent runs detect real drift over time
Diff excerpts — see exactly which lines were added/removed on change
Webhook alerts — optional fire-and-forget JSON POST when a change is detected
Resilient per-URL errors — a failed fetch on one URL never stops the batch

Input

Field	Type	Required	Default	Description
`urls`	`array`	Yes	—	Web pages to check
`selector`	`string`	No	—	CSS selector to scope extraction (defaults to `<body>`)
`sensitivity`	`"any"` \| `"meaningful"`	No	`"meaningful"`	Change detection strictness
`webhookUrl`	`string`	No	—	URL to POST a JSON payload to when a change is detected

Input Example

{
  "urls": ["https://example.com/pricing"],
  "selector": ".pricing-table",
  "sensitivity": "meaningful",
  "webhookUrl": "https://your-app.com/webhooks/change-alert"
}

Output

{
  "url": "https://example.com/pricing",
  "changed": true,
  "change_summary": "Content changed: 2 line(s) added, 1 line(s) removed.",
  "diff_excerpt": "- Starter plan: $9/mo\n+ Starter plan: $12/mo\n+ New Enterprise tier available",
  "checked_at": "2026-07-23T16:00:00.000Z"
}

Field	Description
`url`	The input URL, as provided
`changed`	`true` if the content differs from the last stored snapshot
`change_summary`	Human-readable summary of the change (or lack thereof)
`diff_excerpt`	Up to 8 removed + 8 added lines (`-`/`+` prefixed), truncated to ~2000 characters. `null` if unchanged
`checked_at`	ISO timestamp of this check
`error`	Present only if the fetch/extraction failed for this URL

On the first check for a URL there is no baseline yet, so changed is false and the snapshot is simply stored for future comparisons.

How "meaningful" filtering works

Before hashing/diffing, each extracted line has the following heuristics applied to strip volatile noise:

ISO 8601 timestamps, numeric dates, month-name dates
Clock times (10:30, 10:30:00 AM)
Relative timestamps (5 minutes ago, yesterday, just now)
Engagement counters (1,234 views, 12 comments, 3.4k likes)

These are regex-based heuristics, not a guarantee: some volatile content may occasionally slip through, and rarely meaningful text containing dates/numbers may be stripped along with them. Use sensitivity: "any" if you want a literal raw-text diff instead.

Pricing

Event	Cost
Actor start	$0.02
URL Checked	$0.005

Typical run cost: 100 URLs ≈ $0.02 + 100 × $0.005 = $0.52.

Limitations

Static HTML only — this Actor fetches raw HTML via fetch + Cheerio; it does not execute JavaScript. Pages that render their content client-side (SPAs) may show no extractable text. Use a URL that serves server-rendered HTML, or point at an API/RSS endpoint instead.
Snapshots are capped at 4,000 lines per URL to keep key-value store items small; extremely long pages may be truncated.
Webhook delivery is fire-and-forget with a 10s timeout and no retries — failures are logged but never fail the run.
The named key-value store (semantic-change-snapshots) persists across runs of the same Actor on the same account, so re-running with the same URLs will correctly detect drift since the last run.

Use Cases

Track competitor pricing pages for changes
Monitor legal/ToS pages for updates
Watch documentation pages for silent edits
Alert on job posting or status page changes

Semantic Change Detector

andok/semantic-change-detector

Monitor web pages for meaningful content changes, ignoring noisy timestamps and counters. Optional webhook alerts on change. $0.005/URL + $0.02 start.

Andok

Website Change Monitor

vedder1980/website-change-monitor

Monitor critical web pages for meaningful changes and generate a clean change log for alerts, competitor tracking, and content watchlists.

Daniel Ferreira de Almeida

Website Change & Compliance Monitor

monema/apify-change-monitor

Monitor public pages, policy documents, listings, and competitor content for meaningful changes with persistent state and webhook alerts.

Maarten Vreeburg

Website Change Tracker – Competitor & Content Monitor

conceivable_extension/website-change-tracker

Monitor any web page for content changes. Detects price updates, policy edits, competitor announcements, and new content. Stores page snapshots and alerts on meaningful diffs. PPE: $0.002 no change, $0.008 changed.

joseph fadero

Web Page Change Monitor - Track Website Changes & Get Alerts

scrappy_garden/web-page-change-monitor

Monitor any website for changes automatically. Track content updates, price changes, product availability, news updates. Get instant alerts when pages change. Perfect for competitor monitoring, price tracking, content surveillance, and automated change detection. Export change history to JSON.

Bikram Adhikari

Website Change Detector

technicaldost/website-change-detector

Monitor websites for content changes with visual comparison. Get alerts when pages update.

Technical Dost Solutions

Competitor Change Monitor API

s3nafps/competitor-change-monitor-api

Detect meaningful text changes on public competitor pages between Apify actor runs.

mohamed senator

Website Change Monitor & Alerter

second_coming/website-change-monitor

Monitor web pages for content changes. Track page diffs, get webhook alerts when monitored pages change. Supports CSS selectors for targeting specific sections.

Richard P

Firecrawl Website Change Monitor - Track Page Changes with AI

alizarin_refrigerator-owner/firecrawl-website-change-monitor---track-page-changes-with-ai

Monitor websites for content changes. Get notified when pricing, inventory, competitor pages, or any web content changes. Uses Firecrawl for intelligent change detection. Markdown Comparison JSON Extraction Change Notifications Webhook Integration Scheduled Monitoring

The Howlers

Page Watch — Website Change Monitor & Content Tracker

mfapitools/page-watch

Monitor any URL for content changes with hash-based change detection. Pay per check + per detected change. Ideal for watching competitor pages, docs, pricing, or any public web page.