0xakihiko / gifiddle

A JavaScript/HTML5 GIF viewer and analyzer

gifiddle

gifiddle is a GIF viewer based on JavaScript and HTML5 that runs entirely in a browser.

Now, you may think: "Who the hell would need that? GIFs are supported by browsers since the invention of the WWW!".

That's correct. But wait, there's more!

• A video player interface for frame-precise playback control.
• Detailed information and various rendering modes for analysis and optimization.
• Correct delay handling for non-looping GIF animations.
• Full support of all GIF89a features, including the long-forgotten plain text extension and the "wait for user input" flag, which allows some historical GIFs to be viewed correctly.

Examples

Mixed image/text GIFs (browsers display the images only):

• BOB_89A.GIF - GIF89a introduction by Bob Berry
• STIGR9.GIF - Steel Tiger V9 by Jim Burton
• CG89A.GIF - A GIF with two dogs and text shadow effects

Pure text GIFs (broken in browsers):

• 89AILLUS.GIF - GIF89a illustration
• TEXTTST.GIF - Text test

GIF87a animations:

• ANIPEPSI.GIF - Old Pepsi animation
• BUBBLES2.GIF - Old bubbles animation
• SHINY2.GIF - Another animation by Jim Burton (NSFW)

Cinemagraph examples (activate "Render raw frames" to visualize the optimization):

• cointreau-table-980.gif
• patagonia-cinemagraph.gif
• spg.gif

Compatibility

Most modern browsers in their recent versions (as of 2015) should work. I tested gifiddle with Firefox 36, Chrome 41 and, with a few quirks, Internet Explorer 10. The app makes extensive use of HTML5 and JavaScript features, so don't expect it to run in old browsers.

Also note that gifiddle requires quite a lot of RAM for large GIFs, since every frame needs to be decoded and kept in memory.

Credits

The GIF reading code is mostly based on shachaf's jsgif, modified with a fast LZW implementation from deanm's omggif and a few extensions on my side.