HTTP/2 and HTTP/3 Features
Key features and improvements introduced in HTTP/2 and HTTP/3 over HTTP/1.1.
The features that distinguish HTTP/2 and HTTP/3 from HTTP/1.1, each tagged with the version it belongs to and the problem it addresses: multiplexing, header compression, transport changes in QUIC and connection behavior on mobile networks.
Use it when
- You are explaining why HTTP/2 or HTTP/3 helps a particular workload.
- You are deciding which protocol version to enable or what to measure after enabling it.
Watch out for
- Gains depend on the workload and network; a single large download changes little, many small requests on a lossy network gain the most.
- Server push saw little adoption and was removed from major browsers, so treat it as a historical feature.
The data
13 rows
| Feature | Version | Description | Benefit |
|---|---|---|---|
| Multiplexing | HTTP/2 | Multiple requests and responses over a single TCP connection. | Eliminates head-of-line blocking. |
| Header Compression (HPACK) | HTTP/2 | Compressed headers using a static and dynamic table. | Reduces overhead on every request. |
| Server Push | HTTP/2 | Server can push resources before the client requests them. | Reduces round trips for related resources. |
| Stream Prioritization | HTTP/2 | Requests can be assigned weight and dependency for ordering. | Critical resources can be delivered first. |
| QUIC Transport | HTTP/3 | Built on UDP instead of TCP for connection establishment. | Eliminates TCP handshake + TLS round trips. |
| 0-RTT Resumption | HTTP/3 | Can resume connections with data from the first packet. | Faster page loads for returning users. |
| Connection Migration | HTTP/3 | Connections survive network changes (e.g., WiFi to LTE). | Seamless experience on mobile devices. |
| Binary Framing Layer | HTTP/2 | Messages are split into binary frames carried on numbered streams instead of text lines. | Enables multiplexing and cheaper, less ambiguous parsing. |
| Flow Control | HTTP/2 | Per-stream and per-connection windows limit how much data a sender may transmit. | Prevents one stream from starving others on a shared connection. |
| QPACK Header Compression | HTTP/3 | Header compression redesigned to work with out-of-order streams. | Keeps compression gains without HPACK's head-of-line blocking. |
| No Transport Head-of-Line Blocking | HTTP/3 | Streams are independent in QUIC, so a lost packet delays only its own stream. | Fewer stalls on lossy networks. |
| Built-in TLS 1.3 | HTTP/3 | QUIC integrates the TLS 1.3 handshake into connection setup. | Fewer round trips before data flows, and encryption is mandatory. |
| Alt-Svc Discovery | HTTP/3 | A server advertises HTTP/3 availability through the Alt-Svc header or an HTTPS DNS record. | Lets clients upgrade from TCP-based HTTP without a separate port. |
Fields
The shape of this dataset, read from the data itself: every column, its type and a real value. Agents can use this to plan a query without fetching the whole document.
| Section | Field | Type | Example |
|---|---|---|---|
| data | feature | string | Multiplexing |
| data | version | string | HTTP/2 |
| data | description | string | Multiple requests and responses over a single T… |
| data | benefit | string | Eliminates head-of-line blocking. |
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