gif.js

JavaScript GIF encoder that runs in your browser.

Uses typed arrays and web workers to render each frame in the background, it's really fast!

Demo - http://jnordberg.github.io/gif.js/

Works in browsers supporting: Web Workers, File API and Typed Arrays

Usage

Include gif.js found in dist/ in your page. Also make sure to have gif.worker.js in the same location.

var gif = new GIF({
  workers: 2,
  quality: 10
});

// add an image element
gif.addFrame(imageElement);

// or a canvas element
gif.addFrame(canvasElement, {delay: 200});

// or copy the pixels from a canvas context
gif.addFrame(ctx, {copy: true});

gif.on('finished', function(blob) {
  window.open(URL.createObjectURL(blob));
});

gif.render();

Options

Options can be passed to the constructor or using the setOptions method.

Name	Default	Description
repeat	`0`	repeat count, `-1` = no repeat, `0` = forever
quality	`10`	pixel sample interval, lower is better
workers	`2`	number of web workers to spawn
workerScript	`gif.worker.js`	url to load worker script from
background	`#fff`	background color where source image is transparent
width	`null`	output image width
height	`null`	output image height
transparent	`null`	transparent hex color, `0x00FF00` = green
dither	`false`	dithering method, e.g. `FloydSteinberg-serpentine`
debug	`false`	whether to print debug information to console

If width or height is null image size will be deteremined by first frame added.

Available dithering methods are:

FloydSteinberg
FalseFloydSteinberg
Stucki
Atkinson

You can add -serpentine to use serpentine scanning, e.g. Stucki-serpentine.

addFrame options

Name	Default	Description
delay	`500`	frame delay
copy	`false`	copy the pixel data
dispose	`-1`	frame disposal code. See GIF89a Spec

Acknowledgements

gif.js is based on:

Dithering code contributed by @PAEz and @panrafal

License

The MIT License (MIT)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.