How to Self-Host Changedetection.io: Website Change Monitoring 2026

TL;DR

Changedetection.io (Apache 2.0, ~18K GitHub stars, Python) monitors any website for changes and alerts you. Use it to track product prices, monitor competitor websites, watch for policy updates, or get notified when a sold-out item comes back in stock. Visualping charges $14/month for 25 checks. Changedetection.io is free and self-hosted with unlimited checks.

Key Takeaways

• Changedetection.io: Apache 2.0, ~18K stars, Python — website change monitoring with unlimited checks
• Visual diff: See exactly what changed — highlighted diff view
• CSS selectors: Monitor only a specific section of a page (price div, stock status, etc.)
• JavaScript rendering: Playwright integration handles SPAs and dynamic pages
• Price tracking: Extract and track numeric values over time
• Alerts: Notify via email, Slack, Discord, Telegram, ntfy, and 80+ more

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Part 1: Docker Setup

# docker-compose.yml
services:
  changedetection:
    image: ghcr.io/dgtlmoon/changedetection.io:latest
    container_name: changedetection
    restart: unless-stopped
    ports:
      - "5000:5000"
    volumes:
      - changedetection_data:/datastore
    environment:
      BASE_URL: "https://watch.yourdomain.com"
      TZ: America/Los_Angeles

  # Optional: Playwright for JavaScript-heavy sites:
  playwright-chrome:
    image: browserless/chrome:latest
    container_name: playwright-chrome
    restart: unless-stopped
    environment:
      SCREEN_WIDTH: 1920
      SCREEN_HEIGHT: 1024
      DEFAULT_LAUNCH_ARGS: '["--no-sandbox"]'

volumes:
  changedetection_data:

docker compose up -d

Visit http://your-server:5000

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Part 2: HTTPS with Caddy

watch.yourdomain.com {
    reverse_proxy localhost:5000
}

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Part 3: Add Your First Watch

Basic URL watch (entire page)

1. + Watch URL → https://example.com/product
2. Check interval: Every 4 hours
3. Save

On next check, Changedetection snapshots the page. On subsequent checks, it diffs the new content against the snapshot and alerts on any change.

Target a specific element (CSS selector)

For price tracking, monitor only the price element:

URL: https://amazon.com/dp/PRODUCT_ID
Filter: CSS selector  →  span.price, #priceblock_ourprice, .a-price

Common selectors:

/* Amazon price: */
.a-price .a-offscreen

/* Best Buy price: */
.priceView-customer-price span

/* Walmart price: */
[itemprop="price"]

/* Generic */
[class*="price"]

JavaScript-rendered pages (SPAs)

For sites that load content via JavaScript:

1. Edit Watch → Fetch → Use Browser Steps (Playwright)
2. Select browser: Playwright Chrome
3. Optional: Add browser steps (click, scroll, wait for element)

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Part 4: Notification Setup

ntfy (push notifications to phone)

Settings → Notifications → + Add notification
Type: ntfy
ntfy URL: https://ntfy.yourdomain.com/price-alerts
Priority: High

Telegram

Type: Telegram
Bot Token: your-bot-token
Chat ID: your-chat-id

Email

Settings → SMTP:
SMTP Server: mail.yourdomain.com
Port: 587
Use TLS: Yes
Username: alerts@yourdomain.com
Password: your-password
From: alerts@yourdomain.com

Slack / Discord webhooks

Type: Slack or Discord
Webhook URL: https://hooks.slack.com/services/...

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Part 5: Use Cases

Price tracking

URL: https://store.com/product-page
CSS Filter: .product-price
Alert condition: Price changes
Notification: Telegram/ntfy

Set up a condition:

• Alert when price decreases (.product-price value goes down)
• Alert when stock status changes from "Out of Stock" to "In Stock"

Competitor monitoring

URL: https://competitor.com/pricing
Check interval: Daily
Alert: Any change on the pricing page

Policy / terms change tracking

URL: https://service.com/terms-of-service
Check interval: Weekly
Alert: Any change
Notification: Email

Government/public data

URL: https://city.gov/permits/new-permits
Check interval: Daily
CSS Filter: .permit-list
Alert: New content added

Job postings

URL: https://company.com/careers
CSS Filter: .job-listing
Alert: New items added

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Part 6: Advanced Filtering

Include/Exclude text filters

# Only alert if the change contains these words:
Include text: "In Stock", "Available", "$"

# Ignore changes containing these words (reduces noise):
Exclude text: "Advertisement", "Related products", "Also viewed"

Regex filter

# Extract only specific values using regex:
# Filter type: Regex
# Pattern: \$[\d,]+\.?\d*
# This extracts all dollar prices from the page

XPath selectors

//div[@class='product-price']//span[@itemprop='price']

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Part 7: Browser Steps (Playwright Automation)

For sites that require interaction before showing content:

Browser Steps:
1. Wait for element: .product-price
2. Click: [data-tab="pricing"]  (if content is behind a tab)
3. Scroll to element: #product-details
4. Wait 2000ms  (for animations to complete)
5. Take snapshot

Login-protected pages

Browser Steps:
1. Navigate to: https://site.com/login
2. Fill [name="username"]: your-username
3. Fill [name="password"]: your-password
4. Click: [type="submit"]
5. Wait for navigation
6. Navigate to: https://site.com/protected-page

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Part 8: API

# List watches:
curl "https://watch.yourdomain.com/api/v1/watch" | jq '.[].url'

# Add a watch:
curl -X POST "https://watch.yourdomain.com/api/v1/watch" \
  -H "Content-Type: application/json" \
  -d '{
    "url": "https://example.com/product",
    "tag": "price-tracking",
    "time_between_check": {"hours": 4},
    "include_filters": [".product-price"]
  }'

# Trigger immediate check:
curl -X GET "https://watch.yourdomain.com/api/v1/watch/UUID/history" | jq '.'

# Get watch diff:
curl "https://watch.yourdomain.com/api/v1/watch/UUID/history/latest"

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Maintenance

# Update:
docker compose pull
docker compose up -d

# Backup:
tar -czf changedetection-backup-$(date +%Y%m%d).tar.gz \
  $(docker volume inspect changedetection_changedetection_data --format '{{.Mountpoint}}')

# Logs:
docker compose logs -f changedetection

# Remove old snapshots (auto-cleaned, or manually):
# Settings → Maintenance → Purge old snapshots

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See all open source monitoring tools at OSSAlt.com/categories/devops.