# Website Change Monitor (`aibuildersuse/website-change-monitor`) Actor

Watch any webpage (or a CSS/JSON selector on it) and get a structured text diff when content changes. Keeps state between runs and can alert Slack, Discord, Zapier, Make or n8n. For SaaS pricing pages, prefer Pricing Page Change Monitor.

- **URL**: https://apify.com/aibuildersuse/website-change-monitor.md
- **Developed by:** [AIBuildersUse](https://apify.com/aibuildersuse) (community)
- **Categories:** Developer tools, Automation, SEO tools
- **Security:** Limited permissions
- **Stats:** 2 total users, 1 monthly users, 0.0% runs succeeded, 0 bookmarks
- **User rating**: No ratings yet

## Pricing

$5.00 / 1,000 page checkeds

This Actor is paid per event. You are not charged for the Apify platform usage, but only a fixed price for specific events.

Learn more: https://docs.apify.com/actors/running/actors-in-store.md#pay-per-event

## What's an Apify Actor?

An Actor is a serverless cloud program that runs on the Apify platform. It has two run modes.
In Batch mode, an Actor accepts a well-defined JSON input, performs an action which can take anything from a few seconds to a few hours,
and optionally produces a well-defined JSON output, datasets with results, or files in key-value store.
In Standby mode, an Actor provides a web server which can be used as a website, API, or an MCP server.

Apify vocabulary and the platform model are defined once, in the agent quickstart at https://apify.com/agents.md.

## How to integrate an Actor?

If asked about integration, you help developers integrate Actors into their projects.
You adapt to their stack and deliver integrations that are safe, well-documented, and production-ready.

Do not guess an integration path. Every one of them is in the agent quickstart at https://apify.com/agents.md: the Apify MCP server, Agent Skills with the Apify CLI, the JavaScript and Python clients, the REST API, and the account-free path for an agent with no human to sign in. It also carries the rule on stating cost before the first paid run.

For examples already wired to this Actor's own input schema, see the [API](#api) section below.

Each client library has reference documentation the quickstart does not restate: [JavaScript/TypeScript](https://docs.apify.com/api/client/js/docs.md) (`npm install apify-client`) and [Python](https://docs.apify.com/api/client/python/docs.md) (`pip install apify-client`).

# README

## Website Change Monitor

**Website Change Monitor** watches any list of web pages (or a CSS selector / JSON API response) and tells you exactly what text appeared or disappeared since the last run. Snapshots live in a named key-value store, so scheduled runs compare cleanly. Optional webhook alerts work with Slack, Discord, Zapier, Make and n8n.

> Looking for **SaaS pricing plan/price diffs**? Use [Pricing Page Change Monitor](https://apify.com/aibuildersuse/pricing-page-change-monitor) instead — it understands plan cards and price amounts. This Actor is the general-purpose page watcher.

### What it does

- **Watches any URL** — marketing pages, docs, ToS, blog posts, competitor landing pages, public JSON APIs.
- **Optional CSS selector** so you only diff the region that matters (`main`, `#content`, `.terms`).
- **JSON mode** flattens API responses into `path=value` lines for stable diffs.
- **Auto rendering** — plain HTTP first; headless Chromium only when the page looks empty or JS-gated.
- **Ignore noisy lines** with regexes (timestamps, view counters, copyright years).
- **Webhook** with Slack/Discord-compatible `text`/`content` fields.

### Use cases

- Terms of service / privacy policy change alerts.
- Competitor landing-page or feature-page monitoring.
- Docs and help-center watch for product teams.
- Lightweight JSON API change detection.
- Compliance / brand mention watches on public pages.

### How to use

1. Add the URLs. Optionally add a CSS selector (global or per URL).
2. Run once to save a **baseline**.
3. Schedule (hourly / daily). Later runs output `content_changed` rows with added/removed lines.
4. Optional: add a webhook URL.

### Input

| Field | Description |
| --- | --- |
| `urls` | Pages to watch. Items may include `selector` and `label`. |
| `cssSelector` | Default CSS selector for all pages. |
| `contentMode` | `text` (default) or `json`. |
| `renderMode` | `auto` / `http` / `browser`. |
| `ignoreTextPatterns` | Regexes to ignore when diffing. |
| `maxDiffLines` | Cap added/removed lines in each row (default 40). |
| `includeUnchanged` | Emit `no_change` rows (default on). |
| `webhookUrl`, `webhookHeaders` | Alert destination. |
| `stateStoreName` | Snapshot store (default `website-change-monitor-state`). |
| `maxConcurrency` | Parallel pages (1–10). |
| `proxyConfiguration` | Optional Apify Proxy. |

Example input:

```json
{
  "urls": [
    { "url": "https://example.com/" },
    { "url": "https://news.ycombinator.com/", "selector": "#hnmain" },
    { "url": "https://httpbin.org/json" }
  ],
  "contentMode": "text",
  "renderMode": "auto",
  "ignoreTextPatterns": ["©\\s*\\d{4}"],
  "webhookUrl": "https://hooks.slack.com/services/XXX/YYY/ZZZ"
}
```

### Output

```json
{
  "url": "https://example.com/",
  "checkedAt": "2026-11-06T15:10:00Z",
  "previousCheckedAt": "2026-11-05T15:10:00Z",
  "fetchMethod": "http",
  "changeType": "content_changed",
  "addedCount": 2,
  "removedCount": 1,
  "addedText": ["New headline here", "Updated CTA copy"],
  "removedText": ["Old headline"],
  "lineCount": 18,
  "summary": "Content changed (+2 / -1 lines)"
}
```

#### Change types

| `changeType` | Meaning |
| --- | --- |
| `baseline` | First run: snapshot saved. |
| `content_changed` | Text/JSON content differs from the previous snapshot. |
| `no_change` | Checked, identical. |
| `empty_content` | Loaded but no extractable text. |
| `selector_not_found` / `fetch_error` | Selector or load failure. |

### Pricing

Pay per event: **$0.005 per page checked**. Keep default memory at 512 MB for healthy margins.

### Tips

- Scope with a CSS selector to cut noise from nav/footers.
- Use `ignoreTextPatterns` for clocks, A/B banners and counters.
- For heavy SPAs, set `renderMode` to `browser`.
- For SaaS pricing pages, prefer [Pricing Page Change Monitor](https://apify.com/aibuildersuse/pricing-page-change-monitor). For changelog/status feeds, prefer [SaaS Changelog & Status Page Watcher](https://apify.com/aibuildersuse/saas-changelog-status-watcher).

# Actor input Schema

## `urls` (type: `array`):

Any pages to monitor for content changes. Optional per-URL CSS selector or label: {"url": "...", "selector": "#main"}. Not specialized for SaaS pricing cards — use Pricing Page Change Monitor for that.

## `cssSelector` (type: `string`):

Limit the watched region to this CSS selector, e.g. main, #content, article. Per-URL selector overrides this. Leave empty to watch visible text of the whole page.

## `contentMode` (type: `string`):

text extracts visible text lines (default). json treats the response as JSON and flattens key paths for diffing (useful for APIs). html_text is an alias of text.

## `renderMode` (type: `string`):

auto uses HTTP first and falls back to a headless browser when the page looks empty or blocked. http never uses a browser. browser always renders with Chromium.

## `includeUnchanged` (type: `boolean`):

When on, pages without changes get one no_change row so every run shows what was checked. Turn off to output only real changes.

## `ignoreTextPatterns` (type: `array`):

Lines matching these regexes are ignored when comparing (timestamps, counters, ads).

## `maxDiffLines` (type: `integer`):

Cap how many added/removed lines are included per change row.

## `webhookUrl` (type: `string`):

If set, the Actor POSTs one JSON payload with all detected changes after the run (only when something changed). Works with Slack and Discord incoming webhooks.

## `webhookHeaders` (type: `object`):

Extra HTTP headers to send with the webhook, for example an Authorization header.

## `webhookOnBaseline` (type: `boolean`):

By default the first run of a URL only saves a baseline and does not notify. Turn on to also send baseline rows to the webhook.

## `stateStoreName` (type: `string`):

Name of the key-value store in your account where page snapshots are kept between runs. Letters, digits and hyphens only.

## `maxConcurrency` (type: `integer`):

How many pages to check at the same time. Keep it low (1-3) on small memory.

## `proxyConfiguration` (type: `object`):

Optional. Most pages load without a proxy. Use Apify Proxy only if a site blocks the default IPs.

## Actor input object example

```json
{
  "urls": [
    {
      "url": "https://example.com/"
    },
    {
      "url": "https://news.ycombinator.com/"
    },
    {
      "url": "https://httpbin.org/html"
    }
  ],
  "contentMode": "text",
  "renderMode": "auto",
  "includeUnchanged": true,
  "ignoreTextPatterns": [
    "©\\s*\\d{4}",
    "\\d{1,2}:\\d{2}(:\\d{2})?",
    "\\d+\\s*(views?|comments?)"
  ],
  "maxDiffLines": 40,
  "webhookHeaders": {},
  "webhookOnBaseline": false,
  "stateStoreName": "website-change-monitor-state",
  "maxConcurrency": 3,
  "proxyConfiguration": {
    "useApifyProxy": false
  }
}
```

# Actor output Schema

## `changes` (type: `string`):

No description

## `summary` (type: `string`):

No description

# API

You can run this Actor programmatically using our API. Below are code examples in JavaScript, Python, and CLI, as well as the OpenAPI specification and MCP server setup.

## JavaScript example

```javascript
import { ApifyClient } from 'apify-client';

// Initialize the ApifyClient with your Apify API token
// Replace the '<YOUR_API_TOKEN>' with your token
const client = new ApifyClient({
    token: '<YOUR_API_TOKEN>',
});

// Prepare Actor input
const input = {
    "urls": [
        {
            "url": "https://example.com/"
        },
        {
            "url": "https://news.ycombinator.com/"
        },
        {
            "url": "https://httpbin.org/html"
        }
    ],
    "ignoreTextPatterns": [
        "©\\s*\\d{4}",
        "\\d{1,2}:\\d{2}(:\\d{2})?",
        "\\d+\\s*(views?|comments?)"
    ],
    "proxyConfiguration": {
        "useApifyProxy": false
    }
};

// Run the Actor and wait for it to finish
const run = await client.actor("aibuildersuse/website-change-monitor").call(input);

// Fetch and print Actor results from the run's dataset (if any)
console.log('Results from dataset');
console.log(`💾 Check your data here: https://console.apify.com/storage/datasets/${run.defaultDatasetId}`);
const { items } = await client.dataset(run.defaultDatasetId).listItems();
items.forEach((item) => {
    console.dir(item);
});

// 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/js/docs

```

## Python example

```python
from apify_client import ApifyClient

# Initialize the ApifyClient with your Apify API token
# Replace '<YOUR_API_TOKEN>' with your token.
client = ApifyClient("<YOUR_API_TOKEN>")

# Prepare the Actor input
run_input = {
    "urls": [
        { "url": "https://example.com/" },
        { "url": "https://news.ycombinator.com/" },
        { "url": "https://httpbin.org/html" },
    ],
    "ignoreTextPatterns": [
        "©\\s*\\d{4}",
        "\\d{1,2}:\\d{2}(:\\d{2})?",
        "\\d+\\s*(views?|comments?)",
    ],
    "proxyConfiguration": { "useApifyProxy": False },
}

# Run the Actor and wait for it to finish
run = client.actor("aibuildersuse/website-change-monitor").call(run_input=run_input)

# Fetch and print Actor results from the run's dataset (if there are any)
print(f"💾 Check your data here: https://console.apify.com/storage/datasets/{run.default_dataset_id}")
for item in client.dataset(run.default_dataset_id).iterate_items():
    print(item)

# 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/python/docs/quick-start

```

## CLI example

```bash
echo '{
  "urls": [
    {
      "url": "https://example.com/"
    },
    {
      "url": "https://news.ycombinator.com/"
    },
    {
      "url": "https://httpbin.org/html"
    }
  ],
  "ignoreTextPatterns": [
    "©\\\\s*\\\\d{4}",
    "\\\\d{1,2}:\\\\d{2}(:\\\\d{2})?",
    "\\\\d+\\\\s*(views?|comments?)"
  ],
  "proxyConfiguration": {
    "useApifyProxy": false
  }
}' |
apify call aibuildersuse/website-change-monitor --silent --output-dataset

```

## MCP server setup

```json
{
    "mcpServers": {
        "apify": {
            "type": "http",
            "url": "https://mcp.apify.com/?tools=fetch-actor-details,aibuildersuse/website-change-monitor"
        }
    }
}
```

The hosted server signs you in with OAuth on first connect, so no API token belongs in this config. Clients without OAuth support can send an `Authorization: Bearer <APIFY_API_TOKEN>` header instead, using a token from API & Integrations in Apify Console (https://console.apify.com/settings/integrations).

## OpenAPI specification

Download the OpenAPI definition: https://api.apify.com/v2/actors/AT3bZUeg8iPUwNvs2/builds/x0lIpNMPomEjEf2c1/openapi.json