Simple pricing, measured in freshness.
Free hourly checks. $1 per endpoint for per-minute. Enterprise rates set per target — up to 100 requests per second.
Free
For side projects and keeping a casual eye on things.
- Up to 10 endpoints
- A check every hour
- JSON & web page diffs
- Noise filters & ignore rules
- Email + webhook alerts
- 7-day change history
Pro
Minute-level freshness for prices, inventory and APIs you depend on.
- Unlimited endpoints
- A check every minute (1 RPM)
- Slack, Discord & signed webhooks
- Live SSE stream of diffs
- Custom headers, auth & methods
- Conditions — e.g. mag >= 5
- 90-day history & event replay
- REST API access
Enterprise
Request rates set per target — up to 100 requests per second where the target can take it.
- Custom request rate per target, up to 100 RPS
- Rates tuned to each target’s limits & terms
- Detection within one check interval — sub-second at ≥ 1 RPS
- Bulk monitor API — 10k+ targets
- WebSocket & SSE firehose
- Dedicated egress IPs & regions
- SSO / SAML, audit logs, 99.99% SLA
| Compare plans | Free | Pro | Enterprise |
|---|---|---|---|
| Check frequency | 1 / hour | 1 / minute | Custom per target, up to 100 / s |
| Endpoints | 10 | Unlimited | Unlimited |
| Detection latency | ≤ 60 min | ≤ 60 s | ≤ 1 check interval (sub-second at ≥ 1 RPS) |
| JSON & page diffs | |||
| Noise filters | |||
| Email & webhooks | |||
| Slack & Discord | |||
| SSE stream | |||
| WebSocket firehose | |||
| Conditions & thresholds | |||
| Custom headers & auth | |||
| Bulk monitor API | |||
| History | 7 days | 90 days | Custom |
| Dedicated IPs & regions | |||
| SSO / SAML | |||
| Support | Community | Priority + SLA |
Questions, answered.
What exactly does Diffmonitors watch?
Any URL that answers an HTTP request: JSON and GraphQL APIs, RSS feeds, sitemaps and rendered web pages. JSON gets a structural, field-level diff; pages are reduced to their visible text (optionally scoped by CSS selector) and diffed line by line.
What’s the difference between a check and a change?
A check is one request to your endpoint. A change is emitted only when the response differs from the previous one after your ignore rules are applied — so you pay for freshness, but you’re only notified about real differences.
What do 1 RPM and “up to 100 RPS” mean for my endpoint?
Pro checks each endpoint once per minute (1 request per minute) for $1 per endpoint per month. On Enterprise the request rate is set per target — up to 100 requests per second — depending on what that target can handle: its rate limits, caching and terms. We agree each target’s rate with you; once a change is detected, its diff is delivered within a second.
How do you deal with noisy fields like timestamps?
Ignore rules drop volatile fields such as timestamps, request ids or generation times before diffing. Rules accept bare keys (anywhere in the document) or paths with wildcards like features.*.properties.updated. Try the “Noise filter” toggle in the live demo.
How do I receive diffs?
Email and signed webhooks (with retries) on every plan; Slack and Discord on Pro and Enterprise; a live Server-Sent Events stream on Pro and a WebSocket firehose on Enterprise. Every event carries an RFC 6902 JSON Patch so you can apply changes downstream. Delivery integrations are rolling out to early users now.
Is the live demo real?
Yes. The JSON APIs and Wikipedia pages in the demo are requested live from your browser, and the replayed history — 24 hours, 30 minutes or 30 seconds, depending on the cadence — is rebuilt from each source’s own historical data: the USGS past-week feed, the ISS positions API, Open-Meteo 15-minute data and Wikipedia page revisions. Custom URLs are fetched directly when the site allows cross-origin requests; otherwise you’ll see a clearly labeled simulation — production monitors run from our servers and aren’t limited by CORS.
Can I monitor endpoints that need authentication?
Pro and Enterprise monitors support custom headers, bearer tokens, cookies and non-GET methods. Secrets are encrypted at rest and never included in webhook payloads.
Do you respect rate limits?
Yes. Monitors back off on 429 and 5xx responses, honor Retry-After, and Enterprise plans can use dedicated egress IPs you can allowlist with the provider.