Why animated GIFs get so large
A GIF has no real video compression. Each frame is stored as an indexed-color image, and even with some savings for unchanged regions, the file grows quickly as you add frames or increase the dimensions. A short clip that looks small on screen can still be several megabytes.
The size of a GIF depends mostly on three things: how many frames there are, how many pixels each frame has, and how much changes from frame to frame. Of these, the pixel dimensions are the easiest to control without changing the animation itself.
That is the approach this tool takes. It scales every frame down by a percentage you choose and then re-encodes the animation, keeping the frame order and each frame's original delay.
When shrinking the frames is the right fix
Reducing dimensions is a good fit when a GIF is going somewhere it will be displayed small anyway: an email, a chat message, a forum post or a help-center article. Many of those places have upload limits, and a 100% size GIF is often far larger than the space it fills.
The size drop is larger than the percentage suggests, because pixel count falls with the square of the scale. At 50% scale, both width and height are halved, so each frame has a quarter of the pixels. For example, a 400 by 300 GIF at 50% becomes 200 by 150.
If you need the animation at a specific size, the same idea applies to still pictures with the Image Resizer. To build a new, leaner animation from scratch, try the GIF Maker.
How to compress a GIF
- Drop a GIF onto the upload area or click to browse. Only GIF files are accepted.
- The file name and current size are shown. Move the Scale slider between 20% and 100% in steps of 5. The default is 75%.
- Click Compress GIF. A progress bar runs while each frame is scaled and the animation is re-encoded in your browser. Nothing is uploaded.
- When it finishes, the new size is displayed in green. Compare it to the original size above it.
- Click Download to save the file. It keeps your original name and adds -compressed.gif.
If the result is still too big, lower the scale and run it again from the same source file.
Tips and limits
Scaling reduces dimensions only. The tool does not reduce the number of frames, change the color palette in a way you can control, or alter the frame speed. If your GIF has very many frames, you may still end up with a large file even at a low scale.
Do the arithmetic before you start. An 800 by 600 GIF at 75% becomes 600 by 450, which is about 56% of the original pixels (270,000 compared with 480,000). Check the displayed new size, because the re-encoding can behave differently from the original encoder, and in rare cases the result can even be larger than a file that was already well optimized.
Smaller frames look softer, so keep text-heavy animations at a higher scale. Use the downscaled file only where its reduced size is acceptable and keep your original for any future edits.