Free Tool

Website Uptime Checker

Check if any website is online and healthy. Get a full health report covering DNS, SSL, security headers, performance, and content - with grades for each category.

What You Get

Here's an example of the health report this tool provides. Try it above with any website.

A92/100

Website is Up & Healthy

https://example.com — 187ms response time

Category Grades

DNS
A+
98/100
SSL/TLS
A
95/100
Response
A
90/100
Security
B
80/100

Key Findings

TTFB142ms
SSL CertificateValid (287 days)
HSTSEnabled + Preload
Compressiongzip

The uptime checker performs a deep analysis of your website across seven categories. DNS resolution verifies your domain resolves correctly and measures lookup speed. SSL/TLS checks certificate validity, expiry, and protocol version.

Security headers evaluate protection against common web attacks — HSTS, CSP, clickjacking prevention, and more. Performance measures response time, TTFB, content size, and compression. Content health checks that your page has proper HTML structure (title, meta description, favicon) and isn't returning an error page.

How It Works

1

Enter URL

Type any website URL. We'll resolve the domain, follow redirects, and analyze the full response.

2

Deep Health Analysis

We check DNS, SSL, redirects, response time, TTFB, security headers, compression, and page content in parallel.

3

Get Your Report

View grades for each category with detailed explanations. Copy, share, or download the full report.

Frequently Asked Questions

This tool performs a comprehensive health check on any website. It tests DNS resolution, SSL certificate validity, redirect chains, HTTP response, performance metrics (TTFB, content size, compression), security headers (HSTS, CSP, X-Frame-Options, and more), and content health (title tag, meta description, favicon). Each category receives a grade from A+ to F, plus an overall health score.

Yes, completely free with no signup required. Just enter a URL and get a full health report instantly. There are no daily limits.

TTFB (Time to First Byte) measures how long it takes for your browser to receive the first byte of data from the server after making a request. A fast TTFB (under 200ms) means your server is responding quickly. Slow TTFB can indicate server performance issues, overloaded hosting, or slow database queries. Google uses TTFB as a factor in Core Web Vitals.

Security headers are HTTP response headers that protect your website and visitors from common attacks. Strict-Transport-Security (HSTS) forces HTTPS connections, Content-Security-Policy prevents XSS attacks, X-Frame-Options blocks clickjacking, and X-Content-Type-Options stops MIME-type sniffing. Missing security headers leave your site and users vulnerable to known attack vectors.

HSTS (HTTP Strict Transport Security) is a security header that tells browsers to always connect to your site over HTTPS, even if a user types http://. This prevents protocol downgrade attacks and cookie hijacking. The 'preload' directive goes further by adding your domain to a built-in browser list, so the very first connection is always HTTPS.

The overall grade is an average of all category scores: DNS resolution, SSL/TLS, redirects, response, performance, security headers, and content health. Each category is scored from 0-100 based on specific criteria, then converted to a letter grade (A+ for 95+, A for 90+, B for 80+, C for 70+, D for 60+, F below 60). The overall grade gives you a quick snapshot of your website's health.

Common reasons for low security grades include: missing HSTS header (no HTTPS enforcement), missing Content-Security-Policy (no XSS protection), missing X-Frame-Options (vulnerable to clickjacking), missing X-Content-Type-Options (MIME sniffing risk), not using HTTPS, or using an outdated TLS version. Each missing header reduces your security score.

Yes! exit1.dev offers continuous website and API monitoring with checks every 2 minutes from multiple regions worldwide. You'll get instant alerts via email, Slack, Discord, Microsoft Teams, or webhooks when your site goes down, responds slowly, or has SSL/domain issues. Start free at app.exit1.dev.

Learn More About Website Monitoring

Guides on uptime monitoring, security headers, and website performance.

How to Check If a Website Is Down

Step-by-step guide to verifying outages, checking status codes, and diagnosing server issues.

HTTP Security Headers Explained

Complete checklist of security headers: HSTS, CSP, CORS, and how to implement them.

API Endpoint Monitoring Playbook

Build a comprehensive API monitoring strategy with validation, alerts, and global coverage.

API Observability Automation Toolkit

Automate API monitoring with payload validation, status automation, and incident response.

Need Continuous Uptime Monitoring?

Stop checking manually. exit1.dev monitors your websites 24/7 with checks every 2 minutes from multiple regions. Get instant alerts via email, Slack, Discord, or webhooks when something goes wrong.

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