GIF resizer
Resize animated GIFs without losing the animation. Change dimensions in pixels and keep the timing of each frame. Nothing is uploaded.
Chrome and Edge first. GIF and animated WebP decoding need ImageDecoder; MP4 export also needs WebCodecs H.264 support. Unsupported browsers show a clear message.
Input: up to 100 MB and 150 frames, 4096 pixels per side, and 128 MB of decoded frame pixels. Output: up to 960 pixels per side and 50 MB. Larger animations are rejected, never shortened silently.
GIF output has up to 256 colours per frame and binary transparency. WebP frame delays are rounded to GIF’s 10 ms steps. Very short source delays follow browser decoding behaviour. The chosen loop setting replaces the original repeat count.
GIF output uses gifenc by Matt DesLauriers, MIT. License text. Animation decoding uses your browser.
How to use this tool
Choose a GIF, enter the width or height and keep the aspect ratio if needed. Preview the animation, select Resize GIF, then save the result.
Frequently asked questions
Is it free, and are my files uploaded?
It is free with no account. Your file is decoded and processed on your device. Nothing is uploaded.
Which browsers can use this tool?
Use current Chrome or Edge first. This tool needs the browser ImageDecoder API for GIF or WebP animation. MP4 export also needs a working WebCodecs H.264 encoder. If support is missing, the page explains it and does not export only the first frame.
What are the size limits?
Input: up to 100 MB and 150 frames, 4096 pixels per side, and 128 MB of decoded frame pixels. Output: up to 960 pixels per side and 50 MB. Larger animations are rejected, never shortened silently.
Will it keep animation timing and transparency?
All decoded frames are exported. GIF stores delays in steps of 10 milliseconds, with a 10-millisecond output minimum; WebP delays are rounded with cumulative timing to limit drift. A zero or missing delay uses the browser display delay, or 100 milliseconds if unavailable. GIF frame delays longer than 655.35 seconds cannot be exported. GIF has at most 256 colours per frame and only fully transparent or opaque pixels, so colours and soft transparent edges can change.
Can I choose how the GIF loops?
Yes. Choose loop forever or play once. The output uses your chosen setting rather than copying the source repeat count.
Does the GIF resizer keep the aspect ratio?
Keep aspect ratio is on by default. Change width or height and the other dimension follows. Turn it off to stretch to an exact size.