WebP Express Middleware

Inspired by a post from Cloudinary, this middleware generates and delivers JPG-, PNG- and TIFF-images on the fly as WebP-images if the requesting client supports that format.

WebP is a new image format from Google that provides lossless and lossy compression for images on the web. For more information please read the official documentation or the article on html5rocks.com about image compression.

Installation

npm install webp-middleware

Usage

var http = require('http');
var express = require('express');
var webp = require('webp-middleware');
 
var app = express();
 
app.use(webp(__dirname + '/public', { ... }));
app.use(express.static(__dirname + '/public'));

It is important to insert the webp middleware before the express.static middleware.

First parameter is the path of the static folder.

Second parameter is an optional options object.

You can also have a look into the example folder for examples.

Options

• cacheDir is the directory where the webp files are saved. Default is a folder webp-cache in the executing directory (path.join(process.cwd(), 'webp-cache'))
• preset delegates to the -preset option at cwebp
• quality delegates to the -q option at cwebp
• alphaQuality delegates to the -alpha_q option at cwebp
• method delegates to the -m option at cwebp
• segments delegates to the -segments option at cwebp
• bytes delegates to the -size option at cwebp
• psnr delegates to the -psnr option at cwebp
• size delegates to the -s option at cwebp. Should be an object with width and height keys
• spatialNoiseShaping delegates to the -sns option at cwebp
• filter delegates to the -f option at cwebp
• strong delegates to the -strong option at cwebp. Should be a boolean value
• noStrong delegates to the -nostrong option at cwebp. Should be a boolean value
• partitionLimit delegates to the -partition_limit option at cwebp
• pass delegates to the -pass option at cwebp
• crop delegates to the -crop option at cwebp. Should be an object with width, height, x and y keys
• resize delegates to the -resize option at cwebp. Should be an object with width and height keys
• multiThreading delegates to the -mt option at cwebp. Should be a boolean value
• lowMemory delegates to the -low_memory option at cwebp. Should be a boolean value
• alphaMethod delegates to the -alpha_method option at cwebp
• alphaCleanup delegates to the -alpha_cleanup option at cwebp. Should be a boolean value
• noAlpha delegates to the -noalpha option at cwebp. Should be a boolean value
• lossless delegates to the -lossless option at cwebp. Should be a boolean value
• hint delegates to the -hint option at cwebp
• metadata delegates to the -metadata option at cwebp

License

Licensed under the MIT License.