HTTP/3 and QUIC Technology

What is HTTP/3 and QUIC Protocol?

The internet world has evolved from TCP (Transmission Control Protocol) based HTTP/1.1 and HTTP/2 to UDP (User Datagram Protocol) based HTTP/3It is making a revolutionary transition towards . HTTP/3, which has become indispensable for modern websites and applications as of 2026 , was developed by Google. QUIC (Quick UDP Internet Connections) It is built on protocol.

Key Advantages of HTTP/3

• Low Latency: Handshake times are reduced to a minimum by combining with TLS 1.3 .
• Uninterrupted Connection During Network Changes: When the user switches from Wi-Fi to mobile data (or vice versa), the connection does not drop (Connection Migration).
• Advanced Security: Encryption is buried deep in the protocol; An unencrypted HTTP/3 connection is not possible.

HTTP/3 Installation on Nginx

if VPS or VDS If you are using Nginx on your server, you need 1.25.0 or newer version of Nginx (or a version with quic module) to enable HTTP/3 support. The configuration below shows you how to enable QUIC on a modern Nginx server.

Your server configuration file (usually /etc/nginx/nginx.conf or /etc/nginx/conf.d/domain.conf) and edit the server block:

server {
    # HTTP/3 for UDP 443 portunu dinle (QUIC)
    listen 443 quic reuseport;

    # HTTP/2 ve HTTP/1.1 for TCP 443 portunu dinle (Geriye dönük uyumluluk)
    listen 443 ssl http2;

    server_name ekasunucu.com www.ekasunucu.com;

    # SSL Sertifika Yolları
    ssl_certificate /etc/letsencrypt/live/ekasunucu.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/ekasunucu.com/privkey.pem;

    # TLS 1.3 Zorunlu (QUIC for gereklidir)
    ssl_protocols TLSv1.3;

    # Alt-Svc Başlığı: Tarayıcıya HTTP/3 desteğini bildirir
    # h3=":443"; ma=86400 -> HTTP/3 destekleniyor, 443 portunda, 1 day boyunca hatırla
    add_header Alt-Svc 'h3=":443"; ma=86400';

    # Other ayarlar...
    location / {
        root /var/www/html;
        index index.php index.html;
    }
}

After saving the configuration in your firewall (UFW or iptables) UDP 443 Don't forget to open the port. Works over HTTP/3 UDP!

# Ubuntu/Debian UFW for:
sudo ufw allow 443/udp

# Nginx'i test et ve yeniden başlat:
sudo nginx -t
sudo systemctl restart nginx

HTTP/3 on LiteSpeed Web Server and cPanel

What we offer as Eka Sunucu Web Hosting in all packages LiteSpeed Enterprise We use. LiteSpeed ​​is the first and most stable web server in the world to support HTTP/3 and QUIC protocols.

Steps for cPanel/WHM Users

If you use cPanel and LiteSpeed on your own VPS server, turning on QUIC support is very simple:

1. LiteSpeed WebAdmin ConsoleLogin to (Usually 7080 port).
2. Configuration > Listeners Go to menu.
3. View SSL Listener (443) settings.
4. Enable QUIC Check the option "Yes".
5. Make sure that the UDP 443 port is open on your firewall (ConfigServer Security & Firewall - CSF).

If you are an Eka Sunucu customer, these settings are on our servers. is active by default. You do not need to take any extra action.

One Click HTTP/3 with Cloudflare

If you don't want to deal with complex server-side settings or are using shared hosting, Cloudflare is the easiest solution. CDN Usage As we mentioned in detail in our article, Cloudflare provides HTTP/3 support by passing traffic through itself.

Activation Steps:

1. Log in to the Cloudflare panel and choose your domain name.
2. From the left menu Network Click the tab.
3. Scroll down the page and HTTP/3 (with QUIC) Find the option.
4. key ON Turn it to (On).

After this process, Cloudflare will notify browsers visiting your site. Alt-Svc will automatically initiate the HTTP/3 connection by sending the header.

Test the Setup

After completing the configuration, you should check whether your site is actually broadcasting over HTTP/3 . The most reliable method for this is browser tools.

Control with Chrome DevTools

1. Open your site in Chrome browser.
2. F12 Open Developer Tools by pressing .
3. Network Switch to the (Network) tab.
4. Right click on the column headers in the table and Protocol Check the option.
5. Refresh the page (F5).
6. In the "Protocol" column h3 If you see the message, the transaction is successful!

You can also use online tools:

• HTTP/3 Check
• Geekflare HTTP/3 Test

Note: Browsers may not immediately use HTTP/3 on the first visit. The first connection is usually established with TCP/HTTP2, then Alt-Svc Requests after the header is received are switched to HTTP/3.

2026 SEO Trends and Core Web Vitals

As of 2026 , Google has placed user experience (Page Experience) at the top of its ranking factors. Especially INP (Interaction to Next Paint) The metric measures the responsiveness of the site.

HTTP/3 and QUIC minimize network latencies and connection establishment times by:

• LCP (Largest Contentful Paint) improves time (Images and content load faster).
• It prevents slowdowns caused by network fluctuations on mobile devices.
• It uses the crawl budget efficiently by optimizing the data exchange between the server and the client.

To maximize your website's SEO performance SEO Analysis You can check your current status using our tool.