HTTP/2 is a significant improvement over HTTP/1.1, especially in the speed department. Apache supports HTTP/2 though it's disabled by default.

You can enable HTTP/2 for Apache by installing the http2 module and configure Apache to serve requests using HTTP/2 instead of the default HTTP/1.1.

Steps to enable HTTP/2 on Apache:

  1. Launch terminal application.
  2. Enable http2 module for Apache. 

    $ sudo a2enmod http2 # Ubuntu, Debian and SUSE Enabling module http2. To activate the new configuration, you need to run:   systemctl restart apache2
    • Distribution with a2enmod support can simply run the command above without having to manually enable the required modules.
    • Fedora, CentOS and Red Hat enables the module by default so requires no manual action to enable the modules.

    Related: How to enable or disable Apache modules

    Options Debian, Ubuntu openSUSE and SLES Fedora Core, CentOS, RHEL macOS homebrew xampp
    a2enmod support yes yes no no no no
    Modules to install none
    Module name n/a http2
    Loadmodule directive n/a LoadModule http2_module <module_locations>/mod_http2.so
  3. Add relevant Protocols directive in main Apache configuration file or on a specific virtual server configuration. 

    <VirtualHost *:80>         # .....         # ....         Protocols h2 h2c http/1.1 </VirtualHost>

    Related: Location for Apache VirtualHost configuration

    Related: Configuration options for HTTP/2

  4. Restart Apache service for the changes to take effect. 

    $ sudo systemctl restart apache2 # Ubuntu and Debian $ sudo systemctl restart httpd # CentOS and Red Hat

    Related: How to manage Apache service

  5. Test by accessing the service using curl. 

    $ curl --http2 --head  onlineweb.tools HTTP/1.1 101 Switching Protocols Upgrade: h2c Connection: Upgrade  HTTP/2 200 date: Sun, 00 Jan 1900 00:00:00 GMT server: Apache/2.4.41 (Ubuntu) last-modified: Sat, 08 Feb 2020 14:15:13 GMT etag: W/"2aa6-59e11227347f6" accept-ranges: bytes content-length: 10918 vary: Accept-Encoding content-type: text/html

Guide compatibility:

Operating System
Ubuntu 16.04 LTS (Xenial Xerus)
Ubuntu 16.10 (Yakkety Yak)
Ubuntu 17.04 (Zesty Zapus)
Ubuntu 17.10 (Artful Aardvark)
Ubuntu 18.04 LTS (Bionic Beaver)
Ubuntu 18.10 (Cosmic Cuttlefish)
Ubuntu 19.04 (Disco Dingo)