Is Your Website
Up or Down?
Check any website's real-time status — HTTP status, response time, SSL, DNS, and security headers. One click, accurate results.
Works with or without https://. Press Ctrl+K to focus.
Quick Check
Why SiteDownNow?
Professional-grade monitoring, right in your browser
Real-time Check
Sends actual HTTP requests via proxy. Uses multiple fallback methods for accurate status detection.
Security Audit
HTTPS, HSTS preload, DNSSEC, and security headers check with a clear A–F letter grade.
Response Timing
Millisecond-level response times with sparkline history charts and performance scoring.
DNS Lookup
Google DNS API reveals real IP addresses and DNSSEC validation status instantly.
Auto-Refresh
Automatic rechecks at intervals (30s, 1m, 2m, 5m) with live countdown and alerts on status change.
Analytics
Uptime percentages, response trends, and per-site stats from your local check history.