Domains
Uptime monitoring and site-down alerts
How the five-minute probe decides a site is down, what a recovery looks like, which plans are probed, and the Lock Screen Live Activity.
Updated · 3 min read
Every watched domain is probed over HTTP every five minutes. Free accounts have three domains probed; paid plans probe every domain inside their automated allowance.
Where to see it
- Web: the domain's Uptime module, and Monitor for the portfolio view.
- iOS: the domain's Uptime module. A site going down starts a Live Activity on the Lock Screen and in the Dynamic Island.
- API/MCP:
GET /api/domains/uptime-snapshots,GET /api/domains/downtime-events, the toolsget_uptime_snapshotsandget_downtime_events.
How down is decided
- Each probe has an eight-second timeout and records a snapshot: OK or not, the HTTP status, and the error.
- A domain is marked down on the second consecutive stored failure, not the first. One failed request is a blip; two in a row is a state.
- A single success at any point clears the state and, if a downtime event was open, closes it as recovered with the outage length.
- Failures that originate on our side (a probe run that could not reach anything at all) store nothing, so they can never mark your site down.
The down event's detected_at is backdated to the first of the two failures, so the outage length in the recovery message is honest.
Alerts
A down alert and a recovery alert go through every enabled channel: push to the app (Uptime push, on by default), email on paid plans (Uptime email), and the alert feed. A down event is deduplicated for 25 minutes so a flapping site does not send five alerts; a recovery is one-shot. Site-down pushes are delivered as time-sensitive and break through the app's quiet hours.
The Live Activity (iOS)
When a watched domain goes down, a Live Activity starts on the Lock Screen and in the Dynamic Island: how long it has been down, the server's own evidence line, the last eight checks, and when the next check is due. It ends itself with "Back online after n min" when the site recovers and stays visible for four hours after.
Custom endpoint checks
The probe checks the domain's root. For a specific URL (a login page, an API health endpoint, a checkout), add a custom endpoint check under Monitor. See Custom endpoint checks.
Common questions
My site was down for three minutes and nothing fired. With a five-minute probe and a two-failure rule, an outage shorter than about ten minutes can pass between probes. That is deliberate: the probe exists to catch the outage that lasts, not to page you for a deploy.
The probe says down but the site opens for me. The probe runs from Cloudflare's network. A firewall rule that blocks Cloudflare, a geo-block, or a bot challenge can fail the probe while browsers succeed. The evidence line on the event shows the status or error the probe saw.
Can I stop probing one domain? Yes: the domain's Scan settings can turn its scanning off, or pause it from the domain's menu.
Keep reading
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