HTTP/3 is the latest version of the HTTP protocol. It uses QUIC (UDP-based) instead of TCP, which means faster connection setup, better performance on lossy networks (mobile), and reduced latency. GoZen Host supports HTTP/3 on all plans running LiteSpeed Web Server.

What HTTP/3 Changes

FeatureHTTP/2 (TCP)HTTP/3 (QUIC)
Connection setupTCP handshake + TLS handshake (2-3 round trips)Combined in 1 round trip (0-RTT on reconnect)
Head-of-line blockingOne lost packet blocks the entire connectionOnly the affected stream is blocked
Network switchingConnection drops when switching WiFi to mobileConnection survives network changes
EncryptionTLS is separate from the transportTLS 1.3 is built into the protocol

In practice, HTTP/3 benefits are most noticeable on:

  • Mobile networks with higher packet loss
  • High-latency connections (distant visitors)
  • Sites with many resources (images, scripts, stylesheets loaded in parallel)

For visitors on fast, wired connections close to your server, the difference is minimal.

Do I Need to Enable It?

No. HTTP/3 is enabled by default on GoZen Host’s LiteSpeed servers. There’s nothing to configure on your end.

Your server advertises HTTP/3 support via the alt-svc response header. Browsers that support HTTP/3 (Chrome, Firefox, Edge, Safari) will automatically upgrade to it.

Verifying HTTP/3 Is Working

Method 1: Browser DevTools

  1. Open your site in Chrome
  2. Press F12 > Network tab
  3. Right-click the column headers and enable the Protocol column
  4. Reload the page
  5. Look for h3 in the Protocol column

If you see h3, you’re on HTTP/3. If you see h2, the browser is using HTTP/2 (first visit often uses HTTP/2, subsequent visits upgrade to HTTP/3).

Method 2: Command Line

  curl -I --http3 https://yourdomain.com 2>&1 | head -5
  

Note: curl needs HTTP/3 support compiled in. Not all system versions have it.

Method 3: Online Tool

Use GoZen Health Score to check your site’s protocol support, or try HTTP/3 Check.

When HTTP/3 Doesn’t Work

Cloudflare in Front

If you use Cloudflare as a proxy (orange cloud), the HTTP/3 connection is between the visitor and Cloudflare, not between Cloudflare and your GoZen server. Cloudflare connects to your origin over HTTP/2 or HTTP/1.1.

This is fine. Your visitors still get HTTP/3 benefits. Cloudflare handles the QUIC termination.

To enable HTTP/3 on Cloudflare:

  1. Log into Cloudflare
  2. Go to Speed > Optimization
  3. Enable HTTP/3 (with QUIC)

Firewall Blocking UDP

HTTP/3 uses UDP port 443 instead of TCP port 443. Some corporate firewalls block outbound UDP. If a visitor’s network blocks UDP 443, their browser falls back to HTTP/2 automatically. No action needed on your side.

Non-LiteSpeed Plans

If you’re running on a VPS with Nginx or Apache (not LiteSpeed), HTTP/3 isn’t enabled by default. You’d need to configure it yourself:

  • Nginx: HTTP/3 support requires Nginx 1.25+ compiled with QUIC
  • Apache: no native HTTP/3 support yet

On GoZen shared hosting and WordPress hosting, LiteSpeed handles this for you.

Does HTTP/3 Improve SEO?

Not directly. Google doesn’t use HTTP/3 as a ranking factor. But HTTP/3 improves Core Web Vitals (especially Largest Contentful Paint and First Input Delay) by reducing latency, which are ranking factors.

The bigger win for SEO is LiteSpeed Cache, which drops your Time to First Byte to single-digit milliseconds.

What to Do Next

Last updated 07 Apr 2026, 00:00 +0200. history

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