Brotli Compression

If you look at HTTP Headers as often as I do, you’ve likely noticed something different in Firefox 44 and Chrome 49. In addition to the usual ‘gzip’, ‘deflate’ and ‘sdhc’ , a new value ‘br’ has started to appear for HTTPS connections.





Compared to gzip, Brotli claims to have significantly better (26% smaller) compression density woth comparable decompression speed.

The smaller compressed size allows for better space utilization and faster page loads. We hope that this format will be supported by major browsers in the near future, as the smaller compressed size would give additional benefits to mobile users, such as lower data transfer fees and reduced battery use.


  • Brotli outperforms gzip for typical web assets (e.g. css, html, js) by 17–25 %.
  • Brotli -11 density compared to gzip -9:
  • html (multi-language corpus): 25 % savings
  • js (alexa top 10k): 17 % savings
  • minified js (alexa top 10k): 17 % savings
  • css (alexa top 10k): 20 % savings

NOTE: Brotli is not currently supported Apache HTTPd server (as of 2016feb10), but will likely be added in an upcoming release.[email protected]%3E

Until there is native support, you can pre-compress files by following instructions here…


Sample Tomcat7 setup

There are a few steps that I generally take to setup a new Tomcat server instance, this enables the following:

  • The manager console
  • HTTP compression
  • UTF-8 encoding


  1. tomcat-users.xml – add to bottom:

    <role rolename="manager-gui"/>
    <user username="tomcat" password="s3cr3t" roles="manager-gui"/>

  2. server.xml – add compression and URIEncoding, change port if desired:

    <Connector port="8080" protocol="HTTP/1.1"
    redirectPort="8443" compression="on" URIEncoding="UTF-8" />

  3. server.xml – relocate webapps by adding ../ to appBase

    <Host name="localhost" appBase="../webapps"
    unpackWARs="true" autoDeploy="true">

  4. Restart your server, on Ubuntu use:

    sudo service tomcat7 restart