What are HTTP/2 and HTTP/3?
HTTP (HyperText Transfer Protocol) is the fundamental technology that allows browsers to request and receive content from web servers. HTTP/2 and HTTP/3 are successive versions of this protocol, each designed to improve speed, efficiency, and user experience.
HTTP/2 was introduced in 2015 as an upgrade from HTTP/1.1, enabling multiple requests over a single connection and improving compression. HTTP/3, released in 2022, builds on this foundation using the QUIC protocol – a faster, more resilient transport layer that reduces latency and handles poor network conditions more gracefully.
Why it matters for landing pages
For UK marketing agencies, page load speed directly impacts conversion rates and SEO performance. Google's Core Web Vitals include loading performance, making these protocols essential considerations when optimising landing pages for campaigns.
HTTP/3 is particularly valuable for:
- Mobile users: Better performance on 4G/5G networks with packet loss
- Retargeting campaigns: Faster page transitions improve user experience
- Video content: More efficient handling of multimedia assets
- International audiences: Superior performance over longer, less stable connections
Key differences
HTTP/2 multiplexes requests over TCP, creating a single connection per domain. It's widely supported and sufficient for most UK-based websites, with adoption exceeding 70% globally.
HTTP/3 uses UDP via QUIC, allowing faster connection establishment and smoother handling of network interruptions. It's becoming standard for high-performance sites but requires modern hosting infrastructure and browser support.
Implementation considerations
Most modern hosting providers automatically support HTTP/2. HTTP/3 requires explicit support from your CDN and hosting partner. Content delivery networks (CDNs) like Cloudflare, Akamai, and AWS increasingly offer HTTP/3 as standard.
For agency clients running paid search and display campaigns, faster landing pages mean better Quality Scores in Google Ads and improved ROI. Testing both protocols can reveal performance gains, particularly for audiences on mobile networks.
Best practice
Ensure your hosting infrastructure supports at least HTTP/2. If your target audience includes mobile users or international visitors, investigate HTTP/3 support with your web host or CDN provider.