ngx_brotli

Brotli is a generic-purpose lossless compression algorithm that compresses data using a combination of a modern variant of the LZ77 algorithm, Huffman coding and 2nd order context modeling, with a compression ratio comparable to the best currently available general-purpose compression methods. It is similar in speed with deflate but offers more dense compression.

ngx_brotli is a set of two nginx modules:

• ngx_brotli filter module - used to compress responses on-the-fly,
• ngx_brotli static module - used to serve pre-compressed files.

Table of Contents

• Status
• Installation
• Configuration directives
  • brotli_static
  • brotli
  • brotli_types
  • brotli_buffers
  • brotli_comp_level
  • brotli_window
  • brotli_min_length
• Variables
  • $brotli_ratio
• Sample configuration
• Contributing
• License

Status

Both Brotli library and nginx module are under active development.

Installation

Dynamically loaded

$ cd nginx-1.x.x
$ ./configure --with-compat --add-dynamic-module=/path/to/ngx_brotli
$ make modules

You will need to use exactly the same ./configure arguments as your Nginx configuration and append --with-compat --add-dynamic-module=/path/to/ngx_brotli to the end, otherwise you will get a "module is not binary compatible" error on startup. You can run nginx -V to get the configuration arguments for your Nginx installation.

make modules will result in ngx_http_brotli_filter_module.so and ngx_http_brotli_static_module.so in the objs directory. Copy these to /usr/lib/nginx/modules/ then add the load_module directives to nginx.conf (above the http block):

load_module modules/ngx_http_brotli_filter_module.so;
load_module modules/ngx_http_brotli_static_module.so;

Statically compiled

$ cd nginx-1.x.x
$ ./configure --add-module=/path/to/ngx_brotli
$ make && make install

This will compile the module directly into Nginx.

Configuration directives

brotli_static

• syntax: brotli_static on|off|always
• default: off
• context: http, server, location

Enables or disables checking of the existence of pre-compressed files with.br extension. With the always value, pre-compressed file is used in all cases, without checking if the client supports it.

brotli

• syntax: brotli on|off
• default: off
• context: http, server, location, if

Enables or disables on-the-fly compression of responses.

brotli_types

• syntax: brotli_types <mime_type> [..]
• default: text/html
• context: http, server, location

Enables on-the-fly compression of responses for the specified MIME types in addition to text/html. The special value * matches any MIME type. Responses with the text/html MIME type are always compressed.

brotli_buffers

• syntax: brotli_buffers <number> <size>
• default: 32 4k|16 8k
• context: http, server, location

Deprecated, ignored.

brotli_comp_level

• syntax: brotli_comp_level <level>
• default: 6
• context: http, server, location

Sets on-the-fly compression Brotli quality (compression) level. Acceptable values are in the range from 0 to 11.

brotli_window

• syntax: brotli_window <size>
• default: 512k
• context: http, server, location

Sets Brotli window size. Acceptable values are 1k, 2k, 4k, 8k, 16k, 32k, 64k, 128k, 256k, 512k, 1m, 2m, 4m, 8m and 16m.

brotli_min_length

• syntax: brotli_min_length <length>
• default: 20
• context: http, server, location

Sets the minimum length of a response that will be compressed. The length is determined only from the Content-Length response header field.

Variables

$brotli_ratio

Achieved compression ratio, computed as the ratio between the original and compressed response sizes.

Sample configuration

brotli on;
brotli_comp_level 6;
brotli_static on;
brotli_types application/atom+xml application/javascript application/json application/rss+xml
             application/vnd.ms-fontobject application/x-font-opentype application/x-font-truetype
             application/x-font-ttf application/x-javascript application/xhtml+xml application/xml
             font/eot font/opentype font/otf font/truetype image/svg+xml image/vnd.microsoft.icon
             image/x-icon image/x-win-bitmap text/css text/javascript text/plain text/xml;

Contributing

See Contributing.

License

Copyright (C) 2002-2015 Igor Sysoev
Copyright (C) 2011-2015 Nginx, Inc.
Copyright (C) 2015 Google Inc.
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in the
   documentation and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.