Compress GIFs instantly

Drop a GIF and watch it shrink — everything runs in your browser.

Frequently asked questions

Are my GIFs uploaded to your servers?

Never. All compression runs entirely in your browser using WebAssembly. Your files never leave your device — there are no servers involved at any step.

Is there a file size limit?

There's no hard limit. That said, large files (over 20 MB) take longer to process and use significant browser memory. For anything big, a desktop browser is recommended — mobile devices may struggle or crash on very large GIFs.

How much can I compress without losing quality?

It varies by source GIF. The quality slider lets you find the right balance — higher values preserve more color depth and detail. Use the preview to compare before downloading.

How does 'target size' compression work?

We run a binary search across compression parameters to get as close as possible to your target. Up to 10 passes are made — the result shown is the closest achievable to your target.

What formats are supported?

GIF input and GIF output only. GifMash is specifically optimised for the GIF format using gifsicle compiled to WebAssembly.

Which browsers are supported?

All modern browsers that support WebAssembly: Chrome 57+, Firefox 52+, Safari 11+, Edge 16+. For large files, a desktop browser is strongly recommended.

Is GifMash free?

Yes. GifMash is free to use and requires no account or subscription. It runs entirely in your browser.