Your API Broke. Your Dashboard Still Says 200 OK.
HTTP status codes lie. Visual Sentinel monitors response times, payload validation, SSL chains, and DNS — catching the failures that status codes hide.
Set up in 60 seconds. No credit card required.
“We caught 3 outages in the first week that our old monitor missed.” — Eric D., Powered Storage
What Is API Monitoring?
API monitoring is the practice of continuously testing API endpoints to verify they respond correctly, return valid data, and meet performance targets. Unlike basic uptime checks that only verify a 200 status code, comprehensive API monitoring validates response times, SSL certificate health, DNS resolution, and content integrity. When an API returns 200 OK but sends stale data, malformed JSON, or takes 8 seconds to respond, basic monitors miss it entirely. Visual Sentinel monitors your API endpoints across 6 layers — uptime, performance (TTFB and response time tracking), SSL certificates, DNS records, visual output (for web-facing APIs), and content validation — catching silent failures that traditional monitors cannot detect.
What Our Users Say
“Our payment API was returning 200 but with empty responses for 3 hours. UptimeRobot said everything was fine. Visual Sentinel caught it in under 2 minutes through content monitoring.”
Marcus T.
CTO, FinTech Startup
“We manage 40+ client APIs. Before Visual Sentinel, we had no way to know when response times degraded gradually. The performance tracking catches slow API drift that would have gone unnoticed for weeks.”
Sarah K.
DevOps Lead
“The 6-layer approach is what sold us. SSL expiry alerts saved us from a production outage when our API gateway certificate was about to expire — our old monitor only checked if port 443 was open.”
James R.
Platform Engineer
Response Time Tracking
Monitor TTFB and total response time with historical trends. Get alerted when your API slows down before users complain.
1-Minute Check Intervals
Your API is tested every 60 seconds from multiple regions. Catch failures in under 2 minutes, not hours.
Content Validation
Verify API responses contain expected keywords, structures, or patterns. Catch empty responses, malformed data, and stale caches.
SSL & DNS Monitoring
Track certificate expiry, chain issues, and DNS record changes. Prevent API outages from expired certs or DNS hijacking.
Performance Baselines
Automatic baseline detection spots gradual degradation. Know when your API drifts from normal response times.
10 Alert Channels
Route API alerts to Slack, Discord, PagerDuty, OpsGenie, email, WhatsApp, Telegram, Teams, webhooks, or Prometheus.
Webhook Integration
Trigger automated responses when your API fails. Connect to your incident management workflow via custom webhooks.
How It Works
Add Your API Endpoint
Enter your API URL and configure expected status codes, response time thresholds, and content validation rules.
Configure Alert Channels
Connect Slack, PagerDuty, or any of our 10 notification channels. Set up escalation rules for critical APIs.
Monitor 24/7
We check your API every minute from multiple regions and alert you the moment something deviates from expected behavior.
Frequently Asked Questions
Start Monitoring in 60 Seconds
Starting at $5.40/mo — catch API failures before your users do
Check Your API Free