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H2O is a new generation HTTP server that provides quicker response to users with less CPU utilization when compared to older generation of web servers. Designed from ground-up, the server takes full advantage of HTTP/2 features including prioritized content serving and server push, promising outstanding experience to the visitors of your web site.

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
  • TCP Fast Open
  • TLS
    • session resumption (standalone & memcached)
    • session tickets with automatic key rollover
    • automatic OCSP stapling
    • forward secrecy & fast AEAD ciphers1
    • private key protection using privilege separation
  • static file serving
  • FastCGI
  • reverse proxy
  • scriptable using mruby (Rack-based)
  • graceful restart and self-upgrade



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Verified on

2 June 2020

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Software prerequisites


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