Need a different target?
Enter any availability percentage and see the downtime it allows, and what that downtime could cost you.
Try uptime calculator
Monitor availability the way your users see it.
UptimeRobot checks your websites, APIs, servers and cron jobs from outside your network, confirms a failed check from a second data center before it alerts you, and shows your availability over time.
No credit card required. Nothing to install.
Confirmed before you're alerted.
When a check fails, UptimeRobot re-checks it from a different data center in the same region before alerting you. This filters out failures caused by a single data center or network route. It works on every plan, including Free.
Around 250,000
monitors a day kept from a false down.
Without the re-check, each of them would have gone red while the site was up.
Availability is more than up or down.
A service is available when users can reach it, it returns the right response, and it answers fast enough to use, wherever those users are. A page that loads an error message is up but not available.
Reachable.
The server answers. Ping, port and HTTP checks confirm the connection works.
Correct.
The response is the one you expect: the right status code, the keyword on the page, the right values in your API's JSON.
Fast.
Response time stays under your threshold, so you know when a service is running too slowly.
Everywhere.
Check one monitor from up to four regions, so you catch outages that only hit part of the world.
What you can monitor.
Websites.
HTTP status codes, keyword checks that confirm the right content is on the page, and response time.
APIs.
Status codes and checks on the values in your JSON responses, with custom headers for authentication and other request settings.
Servers and ports.
Ping checks for servers, plus port checks for web, mail, database and SSH services. UDP services too.
DNS.
Alerts when a DNS record changes or stops resolving.
SSL certificates and domains.
Alerts when a certificate error stops visitors from reaching your site, and reminders before your SSL certificate or domain expires.
Cron jobs and background tasks.
Heartbeat monitors expect a request from your job on schedule. If it doesn't arrive, you get an alert.
Third party services.
Choose from 6,000+ providers your product depends on, like Stripe, AWS and Cloudflare, and track their status alongside your own monitors.
Know your availability in numbers.
Every monitor keeps its uptime percentage, incidents and response times, up to 24 months back.
- Incident log. See when each outage started, how long it lasted and what caused it. Filter by date, duration or cause, and export the log.
- Response time charts. See trends over time, per region on multi-location monitors.
- Monthly reports. Get an uptime report by email every month.
- Comments and post-mortems. Add notes to incidents to document what happened and how it was resolved.
How much downtime each availability level allows.
Availability | Downtime per year | Downtime per month |
|---|---|---|
99% | 3 days 15 h 39 min 36 s | 7 h 18 min 18 s |
99.9% | 8 h 45 min 57 s | 43 min 49 s |
99.95% | 4 h 22 min 58 s | 21 min 54 s |
99.99% | 52 min 35 s | 4 min 22 s |
99.999% | 5 min 15 s | 26 s |
The 6 hidden costs of downtime
At €3,000 an hour in sales, the gap between 99.9% and 99.99% is worth up to about €23,700 a year.
Read our article
Alerts that reach the right person.
Send each monitor's alerts to the people who can fix it, on the channel they'll actually see.
- Channels. Email, SMS, voice call, mobile push, Slack, Microsoft Teams, Discord, PagerDuty, webhooks and 20+ integrations in total.
- Alert timing. Get notified only when a monitor has been down for a set number of minutes, and repeat the alert until it's back up.
- Team roles. Give teammates Admin, Write or Read access, and add notify-only seats for people who only need the alerts.
- Maintenance windows. Pause monitoring during planned work, so it doesn't trigger alerts or count against your availability.
Outside-in vs. inside-out.
On-premises tools like PRTG watch your devices from inside your network: servers, switches, bandwidth. UptimeRobot checks your services from outside, the way your users reach them. Many teams run both.
Inside-out (on-premises tools) | Outside-in (UptimeRobot) | |
|---|---|---|
Checks from | A server inside your network | UptimeRobot data centers in up to four regions |
Best at | Device health, internal traffic, hardware | What users can reach: websites, APIs, public ports |
Catches | A failing disk or a busy switch | DNS problems, an expired SSL certificate, a CDN or routing failure between users and your servers |
Runs on | Hardware you maintain | Nothing to install |
Nothing to install, nothing to keep running
Your checks run from our data centers, the way your users reach you, and a failed check gets a second look from another one before we alert you.
50 monitors free. No credit card required.
Share availability with status pages.
Show customers and teammates your current status and uptime history on a page you don't have to host.
- Add your logo, colors and fonts, choose a layout, and decide which uptime percentages and charts to display.
- Public pages on your own domain, like status.example.com, or private pages behind a password.
- Announcements for incidents and planned maintenance, with a clear timeline.
- Email updates to subscribers, who can sign up straight from the page.
What users love about our availability monitoring.
"Ensuring our service is available, I work within the social sector in the public sector, in a Data and Digitization team. Here, we use UptimeRobot to monitor our social workers' main system to ensure that it runs 24/7…"
Rene Larsen
Social Sector
"I have recently moved monitoring to UptimeRobot for some critical links and external facing services within our organization. Internal monitoring programs are great until the internet is down and you don't know because you can't get the alerts out..."
Michael Palmer
Website Administrator
"I can be confident I'll know when the server reboots and I need to turn it back on! I set it and forget it. Until it emails me that we've had an outage."
Bert B.
Head of IT
Frequently asked questions.
Availability monitoring is the continuous process of checking whether IT systems, applications, networks and services are reachable, operational and accessible to users. UptimeRobot does it from outside your network: it checks your websites, APIs and servers at regular intervals, confirms a failed check from a second data center before it alerts you, and keeps a record of your availability for reports, SLAs and status pages.
Uptime measures how often a service responds. Availability also considers whether it returns the expected content and responds within an acceptable time. UptimeRobot monitors both through uptime checks, keyword and API checks, and response time alerts.
Availability is the time a service was up divided by the total time it was monitored, shown as a percentage. For example, about 53 minutes of downtime in a year is 99.99% availability. UptimeRobot calculates availability for every monitor from its check results. Scheduled maintenance windows can be excluded from downtime calculations.
Every 5 minutes on the Free plan, every 60 seconds on Solo, every 30 seconds on Team and every 15 seconds on Scale. Enterprise plans can go faster. Shorter intervals mean you hear about an outage sooner and your availability numbers are more precise.
It depends on the service and your customers' expectations. A target of 99.99% allows about 53 minutes of downtime per year, while 99.9% allows about 8 hours and 46 minutes. Choose a target that reflects how much downtime your service can tolerate.
Yes. You can check one monitor from up to four regions. Each region gets its own status and response time data, and you can set a different response time threshold per region, so you see when an outage only hits part of the world.
Yes, if your users reach your services over the internet. PRTG watches your devices and network from the inside. UptimeRobot checks from the outside whether users can reach your websites, APIs and servers, and alerts you when they can't. Many teams run both.
Yes. The Free plan includes 50 monitors with 5-minute checks for websites, keywords, ping and ports, with email alerts, integrations like Discord and Google Chat, and a status page. Paid plans add faster checks, more monitor types, multi-region monitoring and more alert channels.
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