Free uptime monitoring you can trust at 3 AM
Check websites, APIs, servers and ports every 60 seconds from 3 locations. StatusEagle retries and cross-checks each failure, so an alert means your service is down, not that a network hop blinked.
3 AM alert verification · Zero false alerts
What you can monitor
| Monitor | Answers |
|---|---|
| Does the URL return the expected status, how fast? | Sites, landing pages, REST APIs |
| Is the host reachable, what’s the latency and packet loss? | Servers, VMs, gateways |
| Is the service accepting connections? | Databases, SMTP, SSH, game servers |
| Is expected text present (or an error absent)? | Checkout, login, “200 but broken” pages |
| Did the scheduled job report in on time? | Backups, imports, report generation |
| Is the device up; what are CPU and memory? | Routers, switches, firewalls (SNMP v1/v2c/v3) |
What uptime percentages really allow
“Three nines” sounds close to perfect. In minutes, the difference between targets is large:
Based on an average month of 30.44 days and a year of 365.25 days.
Your monitoring interval should be small relative to your budget. If you promise 99.95% (about 22 minutes a month), 5-minute checks can consume a quarter of that budget before the first alert.
| Availability | Downtime / month | Downtime / year |
|---|---|---|
| 7 h 18 m | 3 d 15 h 40 m | Internal tools, side projects |
| 3 h 39 m | 1 d 19 h 50 m | Marketing sites |
| 43 m 50 s | 8 h 46 m | Most SaaS SLAs |
| 21 m 55 s | 4 h 23 m | Payments, checkout, core APIs |
| 4 m 23 s | 52 m 36 s | Infrastructure providers |
The alert you can trust
An uptime tool is only as useful as the team’s willingness to act on it. If one alert in five turns out to be noise, people start waiting a minute to “see if it clears”. StatusEagle’s rule is simple: a failure must survive a retry and be confirmed from more than one location before it becomes an alert.
Uptime calculator
Type an availability target to see how much downtime it allows. Useful when you’re writing an SLA or deciding what’s realistic. There’s also a full-page uptime and SLA calculator with per-day and per-week figures.
99.9% allows 43 m 50 s of downtime per month.
How long until you know? A worked example
Detection time is the part of an outage nobody sees on a graph. With interval-based monitoring, it has three parts:
So on a 5-minute interval, the worst case before an alert is just over five minutes, and the average is around two and a half. On a 60-second interval, the worst case is just over a minute. If your SLA budget is 22 minutes a month (99.95%), that difference matters.
Monitoring servers that aren’t on the public internet
Ping, port and HTTP checks run from StatusEagle’s monitoring locations, so the target has to be reachable from the internet. For a firewalled server, allow inbound checks from StatusEagle’s monitoring IP addresses publish the IP list and link it here , and only on the port you’re monitoring. For jobs and services that can’t accept inbound traffic at all, flip the direction: have them send a heartbeat out to StatusEagle, which alerts you when one doesn’t arrive.
# crontab: back up at 02:00, then report success 0 2 * * * /usr/local/bin/backup.sh && curl -fsS -m 10 --retry 3 "$HEARTBEAT_URL" > /dev/null The && means the heartbeat is only sent if the backup exits successfully. Copy $HEARTBEAT_URL from the cron monitor in your dashboard.
# crontab: back up at 02:00, then report success 0 2 * * * /usr/local/bin/backup.sh && curl -fsS -m 10 --retry 3 "$HEARTBEAT_URL" > /dev/null
Measuring uptime for an SLA
Five common uptime monitoring mistakes
60-second checks from 3 locations on every paid plan, from $10/month.
10 monitors · no credit card
Related monitoring
Pair these monitoring checks to ensure complete stack coverage.
Frequently asked questions
Still deciding? Start monitoring free and verify your first service in ~2 minutes.
Uptime monitoring is the continuous checking of whether a website, API, server or port is reachable and responding, combined with a record of the percentage of time it was available.
Your first monitor takes about two minutes.
Free plan: 10 monitors, 3 locations, 1 status page. No credit card.