Everything you need to keep client sites online
Proactive monitoring that helps agencies and freelancers catch issues early, reduce support tickets, and stay ahead of client expectations.
Features
Monitoring built for client work
Everything you need to monitor multiple client sites without babysitting dashboards.
Real-time Monitoring
Monitor client sites 24/7 from global locations. Get instant notifications via email, SMS, Slack, or webhooks when issues are detected.
SSL Certificate Tracking
Never let a client's SSL certificate expire unexpectedly. We notify you weeks in advance to prevent security warnings.
DNS Monitoring
Track all DNS records (A, AAAA, CNAME, MX, NS, TXT, SOA) and get alerted as soon as something changes.
Keyword Monitoring
Verify critical content exists on your pages or detect unwanted text like errors, defacements, or broken deployments.
API Monitoring
Send custom HTTP requests and assert on the JSON response body by path and value. Catch silent API failures behind a 200 OK.
Ping Monitoring
ICMP echo from every monitored region. Verify servers, network devices and anything that doesn't speak HTTP — with multi-region consensus to silence regional blips.
Port Monitoring
TCP connection checks for databases, mail servers, SSH and any service listening on a specific port. Measures connect time and reports refused, timed out or unreachable.
Heartbeat Monitoring
A push-based dead man's switch for cron jobs, backups and background workers. Your job pings a unique URL — if a ping goes missing, we open an incident and alert you.
Cron Job Monitoring
Monitor scheduled jobs against their own cron expression and timezone. We expect a ping at each scheduled time and alert the moment a run is missed or fails.
Multi-Location Checks
Verify availability from different geographical regions to detect localized network issues.
Incident Management
Access detailed logs and historical data for every check and incident so you can diagnose issues fast and keep clients informed.
Smart Alerts
Configure notifications through your preferred channels: email, SMS, Slack, Teams, Discord, Webhooks.
Status Pages
Build trust with beautiful, customizable status pages to keep clients and stakeholders informed during incidents.
Team Collaboration
Invite developers and account managers, manage permissions, and keep everyone in the loop.
How It Works
Get started in minutes
Add Client Sites
Enter client site URLs and choose what to monitor: uptime, SSL, DNS, keywords, JSON, ping, TCP ports or heartbeat/cron jobs.
We Monitor 24/7
Our global infrastructure checks client sites every 30 seconds.
Alert Your Team Fast
Get notified in the tools you already use—so you can fix issues before clients notice.
FAQ
Frequently asked questions
What can Sentinel monitor?
Who is Sentinel built for?
How often does Sentinel check my sites?
How will I be alerted when something breaks?
How do I get started?
Is there a free trial?
Ready to catch downtime before your clients do?
Start monitoring client sites with confidence. 14-day free trial, cancel anytime.