Domain expiry monitoring
The registry asked a few times a day when your domain expires, and an alert when the date falls inside your warning window.
Northwind is up.
The monitor is responding.
northwind.example at the registry
Up for 23 h 58 min100% passed
1,438 checks, median 183 ms, all passed
95% under 262 ms
How the check works
A domain expiry monitor asks the registry through RDAP, the structured successor to WHOIS, for the domain's expiry date. It fails when that date is within the warning window you set, 30 days unless changed. The question is asked a few times a day, which is plenty for a date that moves once a year. A registry that publishes no expiry date passes, and the monitor says so, so you know to watch that domain by hand.
A lapsed domain takes everything with it: the site, the mail, the API, and every certificate. Auto-renew fails quietly when a card expires or a registrar account changes hands, and the reminder emails go to an address nobody reads.
When it counts as down
A domain monitor counts as down after two failed checks in a row and as back after one success. Before a failure counts, it is checked again in the same region; only a failure both checks see goes on the record. On Hobby and Pro every other region checks at the same moment, so the page can say down from North America instead of down. A single failed check still appears on the strip with its time and reason, it just does not change the state or send an alert.
Alerts
Each change of state sends one alert: down, and back, with how long it was out. Email is on every plan. Hobby and Pro add Slack, Discord, Microsoft Teams, Telegram, PagerDuty, Opsgenie, Pushover, ntfy and a signed webhook, plus a repeat notice every so many minutes while an outage lasts. Nothing is sent during a maintenance window.
What the status page shows
Every domain monitor gets a strip on the public page. Each bar is one check, its height the response time; amber marks a timeout and red any other failure. Consecutive failures are grouped into one entry with the time and the reason, and the mark stays there for the whole range. A domain monitor going down opens an incident on the page by itself and resolves it on recovery.