Uptime and downtime with 99 % SLA
2025-11-27: I am finally happy to announce availability of an uptime monitoring service which I always wished had existed: uptime mongers. It has some unique features, which are vital for domain name security.
2025-12-06: Refreshed the design of both uptime.is and uptime mongers using Claude Code!
SLA level of 99 % uptime/availability results in the following periods of allowed downtime/unavailability:
- Daily: 14m 24s
- Weekly: 1h 40m 48s
- Monthly: 7h 18m 17s
- Quarterly: 21h 54m 52s
- Yearly: 3d 15h 39m 30s
Direct link to the page with these results: uptime.is/99 (or uptime.is/two-nines)
The SLA calculations assume a requirement of continuous uptime (i.e. 24/7 all year long) with additional approximations as described in the source. uptime.is was originally implemented in newLISP, which had powered uptime and downtime calculations for more than a decade.
For convenience, there are special CEO and SEO friendly links for N nines: three nines, four nines, five nines, six nines etc.