Parcel plugin that precompresses all assets in production mode.

This plugin utilizes @gfx/zopfli, node-zopfli-es and zlib for GZip compression and zlib (Node 11.7.0+) and brotli for Brotli compression.

Installation

npm install parcel-plugin-compress -D

Usage

By default, this plugin doesn't require any extra configuration to get started. If, however, you'd like to be more targeted in how this plugin is applied, you can configure the plugin as needed.

To configure, add a file called .compressrc in your project's root folder, or add a key in your package.json called compress. The available options are below, with the defaults.

{
  // a regular expression to test filenames against
  "test": ".",
  // a number that represents the minimum filesize to compress, in bytes
  "threshold": undefined,
  // Concurrency limit for p-queue
  concurrency: 2,
  // configuration options for gzip compression
  "gzip": {
    "enabled": true,
    "numiterations": 15,
    "blocksplitting": true,
    "blocksplittinglast": false,
    "blocksplittingmax": 15,
    // use zlib instead of zopfli if zlib is true
    "zlib": false,
    "zlibLevel": 9,
    "zlibMemLevel": 9
  },
  // configuration options for brotli compress
  "brotli": {
    "enabled": true,
    "mode": 0, // 0 = generic, 1 = text, 2 = font (used in WOFF 2.0)
    "quality": 11, // 0 - 11, 11 = best
    "lgwin": 24, // 10 - 24    
    "enable_context_modeling": true, // disabling decreases compression ratio in favour of decompression speed
    "lgblock": undefined, // 16 - 24
    "nPostfix": undefined, // 0 - 3
    "nDirect": undefined // 0 to (15 << nPostfix) in steps of (1 << nPostfix)
  },
  // a flag that changes the behavior of the plugin, by default this option is disabled
  // and the plugin compresses all the files it receives via the Parcel bundle object
  // and match the test regular expression
  //	
  // if true the plugin compresses all files in the output directory and subdirectories
  // that match the test regular expression
  compressOutput: false
}

Browser Support for Brotli

Current versions of the major browsers send br in the Accept-Encoding header when the request is sent over TLS

Support introduced in version ...

• Edge 15
• Firefox 44
• Chrome 50
• Safari 11

Server support

To take advantage of precompressed resources you need a server that is able to understand the Accept-Encoding header and serve files ending with .gz and .br accordingly.

Nginx

Nginx supports Gzip compressed files out of the box with the gzip_static directive.

Add this to a http, server or location section and Nginx will automatically search for files ending with .gz when the request contains an Accept-Encoding header with the value gzip.

gzip_static  on;  

See the documentation for more information.

To enable Brotli support you either

• build the ngx_brotli from source:
  https://www.majlovesreg.one/adding-brotli-to-a-built-nginx-instance
• or install a pre-built Nginx from ppa with the brotli module included:
  https://gablaxian.com/blog/brotli-compression
• or use the approach described in this blog post that works without the brotli module:
  https://siipo.la/blog/poor-mans-brotli-serving-brotli-files-without-nginx-brotli-module

Apache HTTP

https://css-tricks.com/brotli-static-compression/
https://blog.desgrange.net/post/2017/04/10/pre-compression-with-gzip-and-brotli-in-apache.html

LightSpeed

Support for Brotli introduced in version 5.2