Uptime and downtime with 99.9999999 % 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 99.9999999 % uptime/availability results in the following periods of allowed downtime/unavailability:
- Daily: 8.6e-05s
- Weekly: 0.0006s
- Monthly: 0.0026s
- Quarterly: 0.0079s
- Yearly: 0.032s
Direct link to the page with these results: uptime.is/99.9999999 (or uptime.is/nine-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.