GIF Speed Changer
Choose a small animated GIF, pick a playback speed, and download a real GIF rebuilt entirely in your browser.
LOCAL GIF89A RE-ENCODER
Change an animated GIF’s playback speed
Decode its frames in this browser, adjust their timing, and download a newly encoded GIF.
A QUICK WALKTHROUGH
How to use this tool
- Choose one animated GIF up to 25 MB, 120 frames, and a 1.92-megapixel canvas.
- Select a speed from 0.25× to 4× and choose whether to preserve the source repeat setting.
- Create the GIF, review its frame count, timing, and actual GIF89a file size, then download it.
A decoded and re-encoded GIF
Browsers can display animated GIFs but do not expose their individual frames through a standard image API. This page reads GIF frame records and LZW image data itself, composites those frames, and writes a fresh GIF89a file with GIF LZW compression. The download has image/gif MIME type and begins with the GIF89a signature.
Speed changes timing, not frame count
Every decoded source frame is kept in order. A faster setting shortens its delay; a slower setting lengthens it. GIF timing is stored in centiseconds, so very short delays round to a minimum of 20 ms and the finished timing can differ by up to one GIF timing tick per frame.
Bounded local processing
Input is limited to 25 MB, 120 frames, 1,600 pixels on either side, and 1.92 megapixels. The resulting GIF is limited to 80 MB. Frames are decoded and encoded one at a time, but the source, current canvas, and completed GIF remain in browser memory until you leave or download. GIF has a 256-color limit; the output uses a fixed palette and flattens transparent pixels onto white.
GOOD TO KNOW
Common questions
Is the result a real GIF?
Yes. It is a newly encoded GIF89a binary with image/gif MIME type, GIF image descriptors, and LZW-compressed pixel data. This tool never relabels another format with a .gif extension.
Will colors or transparency change?
They can. GIF is limited to 256 colors, and this local encoder maps pixels to a fixed palette. The finished GIF has an opaque white background, so source transparency is not retained.
Can I use a static GIF?
A static GIF has only one frame, so changing its speed has no visible effect. The page accepts it and makes a valid one-frame GIF download.
Does this upload my GIF?
No. Parsing, frame compositing, encoding, previewing, and download happen in your current browser.