H2O

the optimized HTTP/1.x, HTTP/2, HTTP/3 server

H2O is a new generation HTTP server that provides quicker response to users with less CPU, memory bandwidth utilization when compared to older generation of web servers. Designed from ground-up, the server implements of HTTP/2 and HTTP/3 taking the advantages of features including new and old content prioritization schemes, server push, 103 Early Hints, promising outstanding experience to the visitors of the web site.

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Explanation of the benchmark charts can be found in the benchmarks page.

Key Features

HTTP/1.0, HTTP/1.1
HTTP/2
- full support for dependency and weight-based prioritization with server-side tweaks
- cache-aware server push
HTTP/3
- full support for Extensible Priorities (RFC 9218)
- fusion AES-GCM engine for fast QUIC packet generation
TCP
- TCP Fast Open
- low latency tweaks
TLS
- automated certificate retrieval using ACME
- session resumption (standalone & memcached)
- session tickets with automatic key rollover
- post-quantum key exchanges
- automatic OCSP stapling
- zerocopy and hardware crypto offloading
- private key protection using privilege separation with support for Intel QuickAssist Technology
static file serving using asynchronous I/O
FastCGI
reverse proxy
- CONNECT and CONNECT-UDP (RFC 9218 a.k.a., MASQUE)
scriptable using mruby (Rack-based)
graceful restart and self-upgrade
BPF-based tracing tool (experimental)

List of the vulnerabilities that have been reported and fixed can be found in the security advisories page of the repository.

URL: https://h2o.examp1e.net/

⇱ H2O - the optimized HTTP server

H2O

Key Features