Website Testing
HTTP/2 Test: Check if Your Site Supports HTTP/2 or HTTP/3
HTTP/2 and HTTP/3 offer significant performance improvements over HTTP/1.1 through request multiplexing, header compression, and server push. Our tool tests which HTTP version your server supports and measures the performance impact of your current protocol version.
Launch in Mission ControlWhat It Measures
This tool detects the HTTP protocol version your server uses (HTTP/1.1, HTTP/2, or HTTP/3/QUIC) and measures the performance difference between them. It tests multiplexing efficiency by loading multiple resources simultaneously and comparing load times per protocol.
How It Works
- Connects to the server using ALPN negotiation to detect HTTP version
- Tests resource loading efficiency with HTTP/1.1 fallback for comparison
- Measures header compression ratio (HPACK for HTTP/2, QPACK for HTTP/3)
- Reports server push capabilities and current protocol version
Why It Matters
HTTP/1.1 limits browsers to 6 simultaneous connections per domain, causing a waterfall queue for pages with many resources. HTTP/2 eliminates this limit with multiplexing, allowing all resources to download simultaneously over one connection. Upgrading from HTTP/1.1 to HTTP/2 typically reduces load times by 20 to 50%.
Understanding Your Results
HTTP/3 (QUIC) is the current best practice for maximum performance, especially on mobile and unreliable connections. HTTP/2 is the minimum standard for any modern website. HTTP/1.1 is considered legacy and results in measurably slower page loads on resource-heavy pages.
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Run HTTP/2 Test Now →Frequently Asked Questions
How do I enable HTTP/2 on my website?
HTTP/2 support depends on your web server and hosting provider. Nginx and Apache both support HTTP/2 natively but it must be enabled in the configuration. Most CDNs (Cloudflare, AWS CloudFront) automatically use HTTP/2. HTTP/3 requires specific UDP port support and is enabled separately.
Does HTTP/2 require HTTPS?
Technically HTTP/2 can work without HTTPS, but in practice all major browsers only implement HTTP/2 over TLS. This means you must have a valid SSL certificate to use HTTP/2 in a real browser environment. HTTP/3 also requires TLS by design.
What is HTTP/3 and should I use it?
HTTP/3 uses QUIC (a UDP-based transport) instead of TCP. QUIC eliminates head-of-line blocking at the transport layer and improves performance on lossy connections like mobile networks. Cloudflare and major CDNs support HTTP/3. Enable it if your infrastructure allows, but HTTP/2 is still a significant improvement over HTTP/1.1.
What is multiplexing in HTTP/2?
HTTP/2 multiplexing allows multiple requests and responses to be interleaved over a single TCP connection simultaneously. HTTP/1.1 requires separate connections for each resource, with browsers limiting to 6 connections per domain. Multiplexing eliminates this bottleneck and removes the need for domain sharding optimization.
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