Definition
A check interval is the frequency at which a monitoring service tests an endpoint — for example, every 1, 2, or 5 minutes. It is the single biggest factor in how quickly downtime is detected: a 1-minute interval can catch an outage within 60 seconds, while a 5-minute interval might take up to five minutes to notice the same failure.
The interval also determines how accurate your uptime measurement is. Short outages that occur entirely between two infrequent checks are never recorded, so a long check interval can quietly overstate your real availability.
Choosing an interval is a trade-off between detection speed and resource use. Faster checks mean quicker alerts and more accurate data, but more requests to your endpoint and, usually, a higher plan tier.
Why It Matters
Detection speed is the whole point of monitoring. If your checkout breaks, the difference between a 1-minute and a 15-minute interval is the difference between catching it before customers do and finding out from angry support tickets. For revenue-critical or customer-facing services, the check interval directly limits how much downtime can happen before you even know.
How It Works
You set an interval per monitor. The service runs a check on that schedule, records the result, and — if a check fails — triggers an alert and opens an incident. Many tools, including Monitoristic, accelerate checks once a monitor is down (checking every 60 seconds regardless of the configured interval) so recovery is detected quickly. Maximum detection delay is roughly equal to your interval.
Real-World Example
Two identical APIs go down for 3 minutes. The first is checked every minute, so the failure is caught on the next check (within 60 seconds) and an alert fires almost immediately. The second is checked every 5 minutes; the outage starts just after a successful check, so it isn't detected until nearly 5 minutes later — and if it had lasted only 2 minutes, it might never have been recorded at all.
Best Practices
- Use 1-2 minute intervals for payment, auth, and checkout endpoints where every minute counts
- Use 5-minute intervals for marketing sites, blogs, and low-stakes pages
- Match your interval to the uptime precision you need — tighter targets require shorter intervals
- Reserve the shortest intervals for your most critical monitors rather than everything
- Remember that down monitors are often re-checked faster, so recovery is detected quickly regardless of interval
Common Mistakes
- Using a long interval on a revenue-critical endpoint and detecting outages far too late
- Expecting accurate uptime figures from infrequent checks that miss short outages
- Setting every monitor to the fastest interval and hitting plan limits unnecessarily
- Forgetting that the check interval caps your worst-case detection time
- Confusing the check interval with the timeout — they are different settings
In Monitoristic
Monitoristic offers tiered check intervals by plan: every 5 minutes on Lite, every 2 minutes on Pro, and every 1 minute on Business. The default for a new monitor is 15 minutes, which you can lower to your plan's minimum. When a monitor goes down, it is checked every 60 seconds until it recovers, so you learn about recovery quickly.