Website Change Monitor: Diff Any Page

Website change detection for any page: find out exactly what changed — the lines that were added and the lines that were removed, not just "something moved".

A competitor's pricing page. A supplier's terms. A careers page. A status page. A government notice. Anything with a URL.

How to use

1. Sign up for Apify — the free plan's monthly credit is enough to try this Actor.
2. Open Website Change Monitor, fill in the input (the form is pre-filled with a working example) and click Start.
3. Watch results stream into the dataset table while the run is going.
4. Export as JSON, CSV, Excel, XML, HTML or RSS — or pull the results from your own code with the Apify API.

How this website change monitor works

The first run records a baseline and returns one baseline row per page (title, size and a text preview), so you can check it is reading the right content. Turn reportFirstRun off to record the baseline silently, with no rows and no charge. Every run after that compares the page and returns a row only when it actually changed.

Noise is filtered out for you: clock times, ISO timestamps and CSRF tokens are ignored automatically, and you can add your own patterns for visit counters or rotating banners.

How to monitor a website for changes

Field	What it does
urls	Pages to watch
selector	Watch only part of the page, e.g. .pricing-table
ignorePatterns	Regular expressions for text that always changes
alertKeywords	Only report when a word like "price" or "discontinued" appears in the change
minChangedCharacters	Ignore tiny edits
reportFirstRun	On by default: the first run returns a baseline row per page (title, size, text preview). Turn off to record it silently

Input reference

Every option at a glance. A minimal input that works as-is:

{
  "urls": [
    "https://news.ycombinator.com/",
    "https://github.com/trending"
  ],
  "reportFirstRun": true,
  "maxResults": 1000
}

All fields:

• urls (Pages to watch) — Any pages: a competitor's pricing page, a careers page, terms of service, a status page, a product listing.
• selector (Watch only this part (CSS selector)) — Optional. For example “.pricing-table” or “main”. Without it the whole page body is compared.
• ignorePatterns (Ignore these patterns) — Regular expressions for text that changes every visit — visit counters, session IDs, “last updated” lines. Clock times and ISO timestamps are ignored automatically.
• alertKeywords (Only alert if these words appear) — Report a change only when one of these words shows up in what was added or removed, e.g. “price”, “discontinued”, “hiring”.
• minChangedCharacters (Minimum change size) — Ignore changes smaller than this many characters. Default 0.
• includeFullText (Include the page text) — Adds the current text of the page to the result, not just the changed lines. Default false.
• reportFirstRun (Report the first run) — The first run returns one "baseline" row per page with its title, size and a text preview, so you can check that the right content is being watched. Turn off to record the baseline silently (not charged). Default true.
• maxResults (Max results) — Total limit. Default 1000.
• proxy (Proxy) — Apify Proxy is used as a fallback when a site blocks a direct request.

What the page change output looks like

One row per changed page:

{
  "url": "https://httpbin.org/uuid",
  "changeType": "baseline",
  "title": null,
  "contentLength": 51,
  "checkedAt": "2026-09-21T11:07:20.774Z"
}

A page that starts returning 404 or 410 is reported as changeType: "unavailable" — a removed product or a pulled job posting is a change worth knowing about.

How fast is it and what does it cost?

3 pages take about 3 seconds. Unchanged pages produce no rows, so a daily watch on 50 pages costs almost nothing until something happens.

Pricing — what you pay per change

This Actor uses pay-per-event pricing: no monthly rental, you pay for the results you get. Prices per 1,000 results by Apify plan:

Event	Free plan	Bronze	Silver	Gold+
change — One page change reported, with the added and removed lines	$3.00	$2.70	$2.55	$2.40

There is also a small start fee of $0.00005 per GB of memory ($0.00005 per run at the default 1 GB). Platform compute is included in the price — you are not billed separately for run time. Set a maximum total charge on the run if you want a hard cap, and use the input limits to control how much is fetched. The current prices are always on the Pricing tab.

Tips

• Start with a small maxResults (say 20) to check the output, then raise it — you only pay per result.
• Keep the default proxy setting — it is only used as a fallback when a direct request is blocked.
• Rows the Actor cannot read are logged and skipped, never charged — check the run log if a count looks low.

Automate & schedule

Run this Actor on autopilot and pull results into your own stack:

• Apify API — start runs, fetch datasets and manage schedules over REST.
• apify-client for JavaScript and apify-client for Python — official SDKs.
• Schedules — run it on a cron to keep your data fresh.
• Webhooks — trigger downstream actions the moment a run finishes.

JavaScript

import { ApifyClient } from 'apify-client';

const client = new ApifyClient({ token: 'MY_APIFY_TOKEN' });
const run = await client.actor('tindacloud/website-change-monitor').call({
    "urls": [
        "https://news.ycombinator.com/",
        "https://github.com/trending"
    ],
    "reportFirstRun": true,
    "maxResults": 1000
});

const { items } = await client.dataset(run.defaultDatasetId).listItems();
console.log(`Got ${items.length} records`);

Python

from apify_client import ApifyClient

client = ApifyClient("MY_APIFY_TOKEN")
run = client.actor("tindacloud/website-change-monitor").call(run_input={
    "urls": [
        "https://news.ycombinator.com/",
        "https://github.com/trending"
    ],
    "reportFirstRun": True,
    "maxResults": 1000
})

for item in client.dataset(run["defaultDatasetId"]).iterate_items():
    print(item)

cURL — run and get the results in one request:

curl -X POST "https://api.apify.com/v2/acts/tindacloud~website-change-monitor/run-sync-get-dataset-items?token=MY_APIFY_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"urls": ["https://news.ycombinator.com/", "https://github.com/trending"], "reportFirstRun": true, "maxResults": 1000}'

Integrate with any app

Connect the dataset to thousands of apps — no code required:

• Make — multi-step automation scenarios.
• Zapier — push new records straight into your CRM or sheet.
• n8n — self-hosted workflows.
• Slack — get notified when a run finishes or finds something new.
• Google Drive / Sheets — auto-export every run to a spreadsheet.
• Airbyte — pipe results into your data warehouse.
• GitHub — trigger runs from commits or releases.
• Webhooks — call your own endpoint when a run succeeds or fails.

Use with AI assistants (MCP)

The output is clean, LLM-ready JSON. Call this Actor from Claude, ChatGPT, Cursor or any agent framework through the Apify MCP server — ask your assistant to "watch these competitor pricing pages and tell me exactly which lines changed" and let it run this Actor for you.

Agent-ready: autonomous payments (x402 & Skyfire)

This Actor is agent-ready — AI agents can discover it, run it and pay for it on their own. It uses pay-per-event pricing and limited permissions, so it qualifies for Apify's agentic payments:

• x402 — an open, HTTP-native payment protocol. Agents pay in USDC through the Apify MCP server — no Apify account needed.
• Skyfire — agent-to-service payments with pre-funded Skyfire tokens.

Building an AI agent, MCP tool or data pipeline? This Actor is ready to plug in and pay as it goes.

Ready-made examples

Open one, change the fields, press Start — nothing to configure:

• Monitor a competitor pricing page for changes
• Website change detection for any page

Frequently asked questions

Do I need an API key or a login?

No. Paste your input, press Start. There is nothing to connect and no account on the target site to create.

How do I export the results?

Every run produces a dataset you can download as JSON, CSV, Excel, XML or HTML, or read through the Apify API from your own code. You can also connect it to Make, Zapier or n8n.

Can I run this on a schedule?

Yes. Apify schedules run it every hour, day or week without you being there. That is the whole point of this Actor: a scheduled run returns only the pages that changed.

Can I call it from Python or JavaScript?

Yes — the Apify API runs any Actor and returns the dataset, and the official Python and JavaScript clients wrap it in a few lines. AI agents can call it too, through Apify's MCP server.

What does it cost?

You pay per result, not per hour. Filters are applied before anything is charged, so narrowing the input directly lowers the bill. Pages that cannot be read are reported in the log and never charged.

Is this data public?

Everything collected here is what any web page shows to anyone without logging in. Check the target site's terms and the rules that apply to you before using the data commercially.

Related scrapers

• Price & Stock Monitor for Any Shop — prices specifically
• Structured Data Extractor — what a page declares about itself
• Website to Markdown for AI & RAG — the full text, cleaned up