SiteAuditLab
Free tool · No sign-up required

Free Website Uptime Checker

Is your site up right now? Check in seconds.

Test any URL for HTTP status, response time, SSL validity, redirect chain, and DNS resolution. Sign up free for continuous 24/7 uptime monitoring with email alerts.

Results in ~10 seconds · Sign up free to save history & set up monitoring

This tool uses the same scanner as the full SiteAuditLab audit — pre-filtered to this category. Run a full scan to see Security, Performance, SEO, Accessibility, Privacy & more together.

What gets checked

HTTP status code (200, 301, 302, 404, 500…)
Response time in milliseconds
SSL/TLS certificate validity
HTTPS redirect chain
DNS resolution success
Connection timeout detection
HTTP → HTTPS redirect verification
Response header presence
Server error detection (5xx)
Client error detection (4xx)
Final URL after redirects
Time-to-first-byte measurement

Frequently asked questions

How do I know if my website is down?

Enter your URL above and we'll probe it immediately from our servers. You'll see the HTTP status code, response time, and whether the SSL certificate is valid. For continuous monitoring with alerts, sign up for a free account and set up an uptime monitor.

What HTTP status codes mean my site is down?

5xx codes (500, 502, 503, 504) indicate server errors — your site is reachable but the server is returning errors. 4xx codes (400, 403, 404) indicate client errors — often configuration issues. A connection timeout or DNS failure means the site is completely unreachable.

How often can I check uptime?

The manual checker runs on demand with no limits. For continuous monitoring with configurable intervals (1, 5, 15, 30, 60 minutes) and email/webhook alerts when your site goes down, sign up for a free account.

What's a good website response time?

Under 200ms TTFB is excellent. 200–500ms is good. 500ms–1s is acceptable. Over 1s indicates performance problems that need attention. Response time includes DNS lookup, TCP connection, SSL handshake, and server processing time.

Will I get alerted if my site goes down?

The manual checker is a one-time test. Sign up for a free account to set up continuous uptime monitoring — we'll check your site every 1–60 minutes and email you (and optionally send a Slack/webhook notification) the moment your site goes down or comes back up.

Want history, scheduled audits, and uptime monitoring?

Sign up free — no credit card