Resize GIF
Change the dimensions of any GIF instantly in your browser. Enter your target width and the height adjusts automatically to preserve aspect ratio. No uploads required.
Resize a GIFNo signup · No uploads · Runs in your browser
Why Resize a GIF?
GIF file size is directly proportional to the number of pixels in each frame multiplied by the number of frames. A GIF that is 800 pixels wide contains 2.8 times as many pixels as one that is 480 pixels wide at the same aspect ratio. Reducing the width from 800 to 480 can cut file size by 60–70% without any changes to the frame rate or animation timing.
Platform size limits make resizing a routine necessity. Slack has a 5 MB limit for inline GIF display. Discord shows GIFs inline up to 8 MB. Twitter/X converts GIFs to video internally but has a 15 MB upload limit. Email clients like Gmail show attached GIFs but many corporate email gateways block attachments over 10 MB. If a GIF is too large for its destination, resizing is usually the fastest fix.
Display requirements are the other common reason to resize. A GIF created for a desktop blog post at 800px wide may be too large to embed in a mobile-first product UI. Resizing to 320px produces a sharp result at mobile dimensions without creating a separate source file.
Common Target Widths by Platform
| Platform / Use Case | Recommended Width |
|---|---|
| GitHub issues and PRs | 480–640 px |
| Slack inline display | 480 px |
| Discord messages | 480–640 px |
| Twitter / X posts | 480–640 px |
| Email (inline attachment) | 320–480 px |
| Mobile app UI / docs | 320 px |
| Desktop web / blog | 640–800 px |
| Full-width hero animation | 1200 px |
How GIF Resizing Works
This tool uses FFmpeg WebAssembly with the Lanczos scaling algorithm. Lanczos is a high-quality resampling filter that applies a windowed sinc function to compute each output pixel from a weighted average of nearby input pixels. The result is sharper edges, less blurring, and fewer aliasing artifacts compared to simpler algorithms like bilinear or nearest-neighbor scaling.
The scale=W:-1 filter tells FFmpeg to set the width to the value you specify and automatically calculate the height to preserve the original aspect ratio. The -1 in the height position is FFmpeg's shorthand for "compute this dimension automatically."
All frames are resized consistently — the animation timing, loop count, and color palette optimization are carried through from the original. Only the pixel dimensions change.
How Resizing Affects File Size
The file size reduction from resizing is quadratic with the width ratio: cutting the width in half cuts the total pixel count (and thus raw frame data) to 25% of the original. In practice, GIF compression recovers some of this — smaller frames compress slightly better — so actual file size reductions are often in the 60–80% range when halving the dimensions.
This makes resizing more effective than frame rate reduction for large GIFs. Cutting the frame rate from 15 fps to 10 fps saves 33% of frames. Cutting the width from 800 px to 480 px saves 64% of pixels per frame and typically results in a more dramatic final file size reduction, especially for GIFs with many frames.
Resize Your GIF Now
Enter your target width in the editor. Height is calculated automatically. No uploads needed.
Open the EditorFrequently Asked Questions
Does resizing a GIF reduce its file size?
Yes, dramatically. File size scales with the number of pixels per frame. Halving the width (and proportionally the height) reduces the pixel count to 25% of the original, which typically reduces the file size by 60–80%. Resizing is one of the most effective ways to bring a large GIF under a platform size limit.
Will resizing reduce the GIF quality?
Downscaling always involves some information loss, but the Lanczos algorithm used by this tool produces the sharpest possible result when reducing size. For most GIFs, scaling down to 480px wide produces a result that looks nearly identical on screen because the display size is usually similar to the output resolution.
Can I make a GIF larger (upscale) with this tool?
Yes — enter a width larger than the original. However, upscaling cannot add detail that was not in the original. The output will look blurry or blocky because the Lanczos filter is interpolating pixels that do not exist in the source. Upscaling only makes sense if the destination display requires a specific larger size.
What width should I use for different platforms?
Common recommendations: 320px for mobile and messaging apps with strict size limits; 480px for general web use and most social platforms (good balance of quality and size); 640px for desktop-primary displays and high-visibility content; 800px or higher for fullscreen or hero animations.
Does the tool change the GIF frame rate when resizing?
No — the resize tool only changes the pixel dimensions. The frame rate and animation speed are preserved exactly from the original GIF. If you also want to reduce frame rate to further shrink the file, use the Compress GIF tool after resizing.