Uptime monitoring · 24/7 global checks
Uptime monitoring that never sleeps
Monitor websites around the clock from 4 global regions, as fast as every 30 seconds on paid plans. Get instant alerts via email, SMS, Slack, or webhooks when something goes wrong.
Response time
Performance over time
Average
186ms
Min
98ms
Max
312ms
Why uptime monitoring
Catch downtime before your clients do
Your clients expect their websites to be online 24/7. When a site goes down, every minute of undetected downtime costs trust, revenue, and reputation. Sentinel checks your sites around the clock (as often as every 30 seconds on paid plans) and alerts you instantly.
- Checks from 4 global regions, as fast as every 30 seconds
- Multi-region verification prevents false alerts
- Full incident history with response time data
30s
Fastest check interval
4
Global regions
99.9%
Uptime SLA
2,880
Daily checks per monitor at 30s
Capabilities
Enterprise-grade monitoring, agency-friendly pricing
Checks as fast as 30 seconds
Industry-leading check frequency on paid plans, so you catch downtime fast, not minutes after your clients do.
Multi-region verification
Checks run from Ashburn, Portland, Nuremberg, and Singapore. We verify from multiple regions before alerting to prevent false positives.
Response time tracking
Track response times over time and spot performance degradation before it becomes full downtime.
Smart notifications
Get alerts through email, SMS, Slack, Discord, Microsoft Teams, or webhooks. Configure per-monitor preferences.
Advanced HTTP options
Custom HTTP methods, headers, request bodies, authentication, accepted status codes, and timeout configuration.
Domain and SSL included
Every uptime monitor also tracks SSL certificate expiry and domain registration expiry automatically.
Global coverage
Every check, verified from four regions
A single flaky network path is not an outage. Before we open an incident, the same check has to fail across regions, so what reaches you is a real problem and not a routing hiccup.
🇺🇸Ashburn, Virginia
ASH
Response
200142ms
Last check
Mar 10, 2026, 14:32:08 GMT-5
🇺🇸Portland, Oregon
PDX
Response
200189ms
Last check
Mar 10, 2026, 14:32:06 GMT-5
🇩🇪Nuremberg, Germany
NBG
Response
200243ms
Last check
Mar 10, 2026, 14:32:04 GMT-5
🇸🇬Singapore
SIN
Response
200312ms
Last check
Mar 10, 2026, 14:32:02 GMT-5
How often does Sentinel check my websites?
Uptime checks run as often as every 30 seconds on paid plans, and the interval you get is set by your plan. That means you find out about downtime fast, often before your clients notice anything is wrong.
Will I get false alarms when a site is actually up?
No. Checks run from four global regions and Sentinel uses consensus across those regions before alerting you, so a single flaky network path won't trigger a false positive.
Will firewalls or bot protection block the checks?
SentinelBot is a verified bot in Cloudflare's Radar directory, so Cloudflare-protected sites recognize our checks as legitimate monitoring traffic rather than challenging them. Every check identifies itself with a documented user agent, and our monitoring IPs are published for allowlisting.
How will I be notified when a site goes down?
Sentinel sends alerts via email, SMS, Slack, Discord, and webhooks. You can route notifications to wherever your team already works.
Can I monitor multiple client sites from one account?
Yes. Sentinel is built for agencies and freelancers managing many sites, so you can run uptime monitors across all of your clients from a single account.
What else can Sentinel monitor besides uptime?
Alongside uptime, Sentinel offers SSL certificate, DNS, domain expiration, keyword, JSON/API response assertion, ICMP ping, TCP port and heartbeat/cron checks, so you can cover a site's full health in one place.
Is there a free trial?
Yes. Paid plans include a 14-day free trial, there is also a free plan, and you can cancel anytime.
Start monitoring your sites today
Set up your first monitor in under 60 seconds.
No card for the free plan · 14-day trial on paid plans · Cancel anytime