---
title: HTTP/2 and HTTP/3
description: HTTP/2 multiplexes many requests over one connection; HTTP/3 uses QUIC over UDP for a faster handshake.
canonical: https://penasihathosting.com/en/hosting-wiki/http2-http3
type: wiki
locale: en
updated: 2026-10-29
author: Willya Randika
---

# HTTP/2 and HTTP/3

## Overview

- **Summary:** HTTP/2 multiplexes many requests over one connection; HTTP/3 uses QUIC over UDP for a faster handshake.
- **Author:** Willya Randika ([profile](/penulis/willya-randika))

## Article

**HTTP/2** and **HTTP/3** are versions of the HTTP protocol that change how browsers fetch multiple assets. HTTP/2 uses one TCP connection with **multiplexing**; HTTP/3 uses **QUIC** over UDP to reduce handshake latency and head-of-line blocking.

## The core differences

| Aspect | HTTP/1.1 | HTTP/2 | HTTP/3 |
| --- | --- | --- | --- |
| Connection | Several connections | One connection, many streams | QUIC/UDP |
| Multiplexing | No | Yes | Yes |
| Header compression | No | HPACK | QPACK |
| Handshake | TCP + TLS | TCP + TLS | QUIC + TLS 1.3 |
| Strength | Broad compatibility | Parallelism | Mobile/lossy networks |

## How to check

In **DevTools → Network**, enable the Protocol column. `h2` means HTTP/2, `h3` means HTTP/3. From a terminal, `curl -I --http2 https://example.com` checks HTTP/2 support. HTTP/3 usually needs a recent `curl` and a specific flag.

## What to watch for

- **HTTPS is required.** Modern browsers only use HTTP/2 and HTTP/3 on secure connections.
- **The server and CDN must support it.** LiteSpeed, Nginx, and major CDNs generally do.
- **It is not a cache replacement.** The protocol speeds up transfer; large assets are still large.
- **HTTP/3 is not always faster.** On stable networks, the difference can be small.
- **Asset priority still matters.** Many streams do not remove the cost of heavy JavaScript and images.

The difference is barely noticeable on a page with one small file. Multiplexing helps when there are many assets, especially on high-latency connections. If the server does not support HTTP/2 yet, prioritize HTTPS and caching before changing protocols. A CDN is often the fastest way to enable HTTP/3, but test in staging first. Check the header on every asset type as well.

## FAQ

<Accordion>
  <AccordionItem title="Is HTTP/2 faster than HTTP/1.1?">
    For pages with many assets, usually yes, because multiplexing removes connection queuing.
  </AccordionItem>
  <AccordionItem title="Is HTTP/3 required?">
    No. HTTP/2 is enough for many sites. HTTP/3 helps on mobile or lossy networks.
  </AccordionItem>
  <AccordionItem title="How do I enable HTTP/2?">
    Enable HTTPS, then make sure the server (LiteSpeed/Nginx) or CDN supports HTTP/2. Most modern hosting enables it automatically.
  </AccordionItem>
</Accordion>