99.9% uptime — three nines.
99.9% uptime allows about 8 hours and 45 minutes of downtime per year. That's roughly a minute and a half per day. This is the most common SLA target for SaaS products and web applications. It's achievable without heroic infrastructure efforts, but it requires real monitoring and a plan for when things break.
Maximum allowed downtime
Per day
1m 26s
Per week
10m 5s
Per month
43m 50s
Per year
8h 45m 36s
WHO NEEDS IT
Who targets 99.9%
Most SaaS products, web applications, APIs, marketing sites that matter. The standard target for teams that take uptime seriously but aren't building life-critical systems.
WHAT IT TAKES
How to achieve three nines
Uptime monitoring with alerting, a documented incident response process, automated deployments with rollback capability, and basic redundancy (at minimum, the ability to recover quickly from a single failure).
Other uptime tiers
Measure your actual uptime.
Larm uses multi-probe voting to verify outages before alerting — so false positives don't eat into your uptime budget.