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h2c - A Simple HTTP/2 Command-Line Client

h2c is a simple HTTP/2 command-line client, like curl.

While curl terminates after each request/response cycle, h2c runs a background process to keep connections open. That way, h2c may receive asynchronous push messages from the server.

h2c is currently in a very early stage. The best way to learn about it is to read the blog posts on


h2c dump

h2c command line

Basic Usage

h2c start &
h2c connect
h2c get /index.html
h2c stop

Command Overview

For a complete list of available commands, run h2c --help.

  • h2c start [options] Start the h2c process. The h2c process must be started before running any other command.
  • h2c connect [options] <host>:<port> Connect to a server using https
  • h2c disconnect Disconnect from server
  • h2c get [options] <path> Perform a GET request
  • h2c post [options] <path> Perform a POST request
  • h2c set <header-name> <header-value> Set a header. The header will be valid for all subsequent requests.
  • h2c unset <header-name> [<header-value>] Undo 'h2c set'.
  • h2c ping Send a ping.
  • h2c pid Show the process id of the h2c process.
  • h2c push-list List responses that are available as push promises.
  • h2c stream-info List streams and their states.
  • h2c stop Stop the h2c process
  • h2c wiretap <localhost:port> <remotehost:port> Listen on localhost:port and forward all traffic to remotehost:port.

How to Download and Run

Binary releases are available on the GitHub Releases.

  1. Download the latest release ZIP file:
  2. Extract the ZIP file
  3. Find the executable for your system in the bin folder:
  • Linux: h2c_linux_amd64
  • OS X: h2c_darwin_amd64
  • Windows: h2c_windows_amd64.exe
  1. Rename that executable to h2c, or h2c.exe on Windows
  2. Move the executable into a folder on your PATH.

How to Build from Source

h2c is developed with Go 1.6. The external dependencies are located in the vendor/ directory. In Go 1.6, the vendor/ directory will be used by default. In order to build h2c with Go 1.5, you must enable the Go 1.5 vendor handling by setting the environment variable GO15VENDOREXPERIMENT to 1.

The following command will download, compile, and install h2c:

go get

Related Work

h2c uses parts of Brad Fitzpatrick's HTTP/2 support for Go. There is an HTTP/2 console debugger included in bradfitz/http2, but just like h2c, it is currently only a quick few hour hack, so it is hard to tell if they aim at the same kind of tool.


h2c is licensed under the Apache License, Version 2.0.

h2c is implemented in Go and uses Go's standard library, which is licensed under Google's Go license, which is a variant of the BSD License.

The following 3rd party libraries are used: