HTTP3 Checker - Test Your Website for HTTP3 Support
Discover if your website is using the latest HTTP3 protocol for faster, more reliable connections
example.com
QUIC is supported
HTTP/3 is supported
HTTP/3 Check established a QUIC connection for all attempts made with the given endpoint. The server is using HTTP/2. See the metrics below for more information.
Zero Round Trip Time Resumption (0-RTT)
The QUIC handshake for this connection was completed without any additional round-trips.
QUIC Versions
These are the QUIC versions supported by this QUIC endpoint.
| Connection ID | Packet RX | Handshake Done |
|---|---|---|
| 5ababd60... | 2.74 | 6.39 |
HTTP/3 Server Information
Response Headers
| Header | Value |
|---|---|
| content-type | text/html |
| etag | "84238dfc8092e5d9c0dac8ef93371a07:1736799080.121134" |
| last-modified | Mon, 13 Jan 2025 20:11:20 GMT |
| cache-control | max-age=2049 |
| date | Fri, 04 Apr 2025 10:12:58 GMT |
| alt-svc | h3=":443"; ma=93600,h3-29=":443"; ma=93600,quic=":443"; ma=93600; v="43" |
HTTP/3 Statistics
Zero Round Trip Time Resumption (0-RTT)
The QUIC handshake for this connection was completed without any additional round-trips.
QUIC Versions
These are the QUIC versions supported by this QUIC endpoint.
Connection ID
This unique identifier for a QUIC connection is used to ensure that changes to an endpoint's lower network layer address (UDP/IP) does not affect the delivery of the QUIC connection's packets.
This tool attempts two connections to test the server's 0-RTT capabilities. During the first connection, the client receives important handshake material from the server. With 0-RTT, the client can start to send data immediately if it uses this handshake material when it creates the second connection.
Packet RX
This value represents the time between the first packet sent and the first packet received (measured in milliseconds).
Handshake Done
This value represents the time between when the first packet is sent and when the handshake is completed (measured in milliseconds).
Take notice of the difference in this metric between the first connection and the second connection. Using 0-RTT, future connections (i.e. the second connection) can complete the handshake much faster than the original connection.