HTTP/2 Checker

Overview

The HTTP/2 Checker is a powerful tool designed for developers, DevOps engineers, and SEO specialists to verify if a website is utilizing modern network protocols like HTTP/2 or HTTP/3 (QUIC). These newer protocols offer significant performance improvements over the older HTTP/1.1 standard, including multiplexing, header compression, and server push, leading to faster page load times and a better user experience.

This tool allows you to enter any website URL and get a detailed report on the negotiated protocol, redirect chains, connection timings, and relevant server headers.

How to Use the Tool

1. Enter a URL: In the input field, type or paste the full URL of the website you want to check (e.g., https://example.com). If you omit the protocol (http:// or https://), the tool will default to https://.
2. Set Options (Optional):
   • Timeout: Adjust the maximum time the tool will wait for a response from the server.
   • Follow Redirects: By default, the tool follows all HTTP redirects to check the protocol of the final destination. You can disable this to check the protocol of the initial URL only.
3. Click "Check": The tool will send a request to the server and analyze the connection.
4. Review the Results: The output area will display the findings.

Understanding the Output

• Final URL: The ultimate destination URL after all redirects have been followed.
• Negotiated Protocol: The primary result, indicating whether the site uses HTTP/2, HTTP/3, HTTP/1.1, or an Unknown protocol.
• Status: A quick summary of whether the check was successful or encountered an error.
• Total Connection Time: The time taken for the entire connection process, from DNS lookup to receiving the first byte of the response.
• Redirect Chain: If redirects occurred, this section lists each step, including the source URL, the redirect status code (e.g., 301, 302), and the destination URL.
• Server Headers: A selection of important HTTP response headers from the final destination, such as:
  • Server: Often identifies the web server software.
  • Alt-Svc: The "Alternative-Service" header, which is a crucial hint for browsers that HTTP/3 is available. If you see this header with h3 in it, the site is advertising HTTP/3 support.

What are HTTP/2 and HTTP/3?

HTTP/1.1

The traditional protocol used for years. It processes requests sequentially, meaning the browser has to wait for one request to finish before starting the next on the same connection. This can lead to "head-of-line blocking" and slower performance on complex websites.

HTTP/2

A major revision that introduces multiplexing, allowing multiple requests and responses to be sent at the same time over a single TCP connection. This eliminates head-of-line blocking and dramatically improves speed. It also includes header compression (HPACK) to reduce overhead. HTTP/2 is now widely supported by modern browsers and web servers.

HTTP/3

The next evolution, which runs over a new transport protocol called QUIC instead of TCP. QUIC is designed to be faster and more reliable, especially on unstable networks (like mobile). It further reduces connection setup time and improves how it handles packet loss, making it even more performant than HTTP/2.

Privacy Note

This tool makes a direct, one-time request from our server to the URL you provide. We do not store the URL you enter or the content of the website. The check is ephemeral and performed solely to analyze the connection protocol and headers for your information.