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Version: Next

HTTP/3 Protocol

HTTP/3 is the third major version of the Hypertext Transfer Protocol (HTTP). Unlike its predecessors which rely on TCP, HTTP/3 is based on QUIC (Quick UDP Internet Connections) protocol. It brings several benefits that collectively result in reduced latency and improved performance:

  • enabling seamless transition between different network connections, such as switching from Wi-Fi to mobile data.
  • eliminating head-of-line blocking, so that a lost packet does not block all streams.
  • negotiating TLS versions at the same time as the TLS handshakes, allowing for faster connections.
  • providing encryption by default, ensuring that all data transmitted over an HTTP/3 connection is protected and confidential.
  • providing zero round-trip time (0-RTT) when communicating with servers that clients already established connections to.

APISIX currently supports HTTP/3 connections between downstream clients and APISIX. HTTP/3 connections with upstream services are not yet supported, and contributions are welcomed.


This feature is currently experimental and not recommended for production use.

This document will show you how to configure APISIX to enable HTTP/3 connections between client and APISIX and document a few known issues.


Enable HTTP/3 in APISIX#

Enable HTTP/3 on port 9443 (or a different port) by adding the following configurations to APISIX's config.yaml configuration file:

- port: 9443
enable_http3: true
ssl_protocols: TLSv1.3

If you are deploying APISIX using Docker, make sure to allow UDP in the HTTP3 port, such as -p 9443:9443/udp.

Then reload APISIX for configuration changes to take effect:

apisix reload

Generate Certificates and Keys#

HTTP/3 requires TLS. You can leverage the purchased certificates or self-generate them, whichever applicable.

To self-generate, first generate the certificate authority (CA) key and certificate:

openssl genrsa -out ca.key 2048 && \
openssl req -new -sha256 -key ca.key -out ca.csr -subj "/CN=ROOTCA" && \
openssl x509 -req -days 36500 -sha256 -extensions v3_ca -signkey ca.key -in ca.csr -out ca.crt

Next, generate the key and certificate with a common name for APISIX, and sign with the CA certificate:

openssl genrsa -out server.key 2048 && \
openssl req -new -sha256 -key server.key -out server.csr -subj "/" && \
openssl x509 -req -days 36500 -sha256 -extensions v3_req \
-CA ca.crt -CAkey ca.key -CAserial -CAcreateserial \
-in server.csr -out server.crt

Configure HTTPS#

Optionally load the content stored in server.crt and server.key into shell variables:

server_cert=$(cat server.crt)
server_key=$(cat server.key)

Create an SSL certificate object to save the server certificate and its key:

curl -i "" -X PUT -d '
"id": "quickstart-tls-client-ssl",
"sni": "",
"cert": "'"${server_cert}"'",
"key": "'"${server_key}"'"

Create a Route#

Create a sample route to

curl "" -X PUT -d '
"upstream": {
"nodes": {
"": 1

Verify HTTP/3 Connections#

Install static-curl or any other curl executable that has HTTP/3 support.

Send a request to the route:

curl -kv --http3-only \
-H "Host:" \
--resolve "" ""

You should receive an HTTP/3 200 response similar to the following:

* Added to DNS cache
* Hostname was found in DNS cache
* Trying
* QUIC cipher selection: TLS_AES_128_GCM_SHA256:TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256:TLS_AES_128_CCM_SHA256
* Skipped certificate verification
* Connected to ( port 9443
* using HTTP/3
* [HTTP/3] [0] OPENED stream for
* [HTTP/3] [0] [:method: GET]
* [HTTP/3] [0] [:scheme: https]
* [HTTP/3] [0] [:authority:]
* [HTTP/3] [0] [:path: /get]
* [HTTP/3] [0] [user-agent: curl/8.7.1]
* [HTTP/3] [0] [accept: */*]
> GET /get HTTP/3
> Host:
> User-Agent: curl/8.7.1
> Accept: */*
* Request completely sent off
< HTTP/3 200
"args": {},
"headers": {
"Accept": "*/*",
"Content-Length": "0",
"Host": "",
"User-Agent": "curl/8.7.1",
"X-Amzn-Trace-Id": "Root=1-6656013a-27da6b6a34d98e3e79baaf5b",
"X-Forwarded-Host": ""
"origin": ",",
"url": ""
* Connection #0 to host left intact

Known Issues#

  • For APISIX-3.9, test cases of Tongsuo will fail because the Tongsuo does not support QUIC TLS.
  • APISIX-3.9 is based on NGINX-1.25.3 with vulnerabilities in HTTP/3 (CVE-2024-24989, CVE-2024-24990).