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Uptime and downtime with 98.5 % SLA

2025-11-27: It's always DNS, isn't it? I built an uptime monitoring service uptime mongers to monitor the DNS security issues that standard services ignore: parent zone delegation changes, stale DNSSEC signatures, expired RRSIGs. Other check types: PING, HTTP, TOR, TCP, PUSH.

SLA & Uptime Calculator

How much downtime corresponds to your SLA?

%
(enter SLA level and hit the <enter> key)

SLA level of 98.5 % uptime results in the following periods of allowed downtime:

Daily 21m 36s
Weekly 2h 31m 12s
Monthly 10h 57m 26s
Quarterly 1d 8h 52m 19s
Yearly 5d 11h 29m 14s

Direct link to the page with these results: uptime.is/98.5

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.