Screenshot Happy Get a free key
Website monitoring

Get a webhook when a page actually changes

Point Screenshot Happy at a URL and it checks it on a schedule, compares the new capture against the last one, and calls your webhook only when the visual difference crosses a threshold you set.

Read the monitoring docs Read the docs
How it works

Create a monitor, get a webhook on change

Same capture engine as /screenshot, running on a schedule. Requires a real API key — the public demo key can't create monitors.

curl -X POST "https://screenshot-api-production-ffd7.up.railway.app/monitors" \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "url": "https://example.com/pricing",
    "webhook_url": "https://your-server.com/webhook",
    "frecuencia_minutos": 60,
    "umbral_diferencia": 5
  }'

frecuencia_minutos is the check interval — 15 minutes is the hard minimum for every plan. umbral_diferencia is the percentage of changed pixels that counts as a real change (default 5). When a change is detected, Screenshot Happy POSTs to your webhook, with up to 3 delivery attempts (immediately, then after 5s, then after 30s) if your endpoint doesn't return a 2xx response:

{
  "monitor_id": 4,
  "url": "https://example.com/pricing",
  "comprobado_en": "2026-09-28T12:00:00.000Z",
  "cambio_detectado": true,
  "diferencia_porcentaje": 12.4
}

Manage monitors with GET /monitors (lists yours, with the last result and last check time) and DELETE /monitors/:id.

Where this is used

Use cases

Competitor & vendor tracking

Get notified when a competitor's pricing page or a vendor's terms actually change, instead of checking manually.

Agencies

Watch client sites for unexpected visual changes without checking each one by hand.

SaaS & e-commerce

Monitor a status page, a listing or a promo page and react automatically when its content changes.

Pricing

Every plan includes monitoring

Monitored pages and check frequency scale with your plan: Free gives 3 monitored pages checked every 6h; Starter (€9/month) gives 20 pages checked every 1h with webhook alerts; Growth (€29/month) gives 100 pages checked every 15–30 min. Full details in the docs.

Get a free API key

One monitor check runs at a time across the whole service by design — today, with few customers, this is invisible, but the check frequency your plan promises is a target, not a hard real-time guarantee, until this scales further. We'd rather say that here than have it be a surprise.