キレ

Compress GIF

In your browser, no upload

GIF

at most the size you pick · timing kept

GIF

GIF → a smaller GIF

Specification

6 rows
Compress GIF specification
ItemValueNotes
InputGIFStill or animated
OutputGIFThe same frames, delays and loop count
Sizes256 KB, 500 KB, 1 MB, 2 MB, 5 MB, 10 MB, 15 MBOnly sizes smaller than the file; 1 MB counted as 1,000,000 bytes
Steps7Rewritten first, then fewer colours, then a smaller picture
QualityNo loss at the first stepWhen every frame’s colours fit; otherwise re-saved
Processed inThis browserNot sent to a server

What happens

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What happens, and why

Drop a GIF and this page writes it at every step, keeps each, and offers the sizes below the file’s own that a step reaches — 256 KB, 500 KB, 1 MB, 2 MB, 5 MB, 10 MB, 15 MB — with the step each one takes on its button. Press one and the file is handed over at once: it was already written, so the size on the button is the size you get. A GIF is not sent anywhere; it is taken apart and put back together in this tab.

The first step changes nothing you can see. Every frame is written again at its own size with all its colours, but storing only the rectangle that changed since the frame before — how GIF tools store animations to keep them small. A GIF saved as whole frames often shrinks a great deal this way, and when every frame’s colours fit, not one pixel changes and the badge says no quality was lost.

After that each step gives something up, a little at a time: fewer colours in each frame (a GIF’s pixels are palette numbers, so 256 colours take eight bits a pixel and 64 take six), then a smaller picture, then both, down to 25% of the width with 32 colours. Colours and size come down in turn because taking either all the way first looks worse at the same file size. Frame count, every frame’s delay and the loop count stay as they were at every step.

FAQ

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Will it look worse

Not at the first step, when every frame’s colours fit: the pixels are the source’s and the badge says so. Every step after gives something up, and the button says what — fewer colours show as banding in gradients, a smaller picture as fewer pixels. Each size takes the least change that fits it.

Why is it faster or slower than before

It is not: every frame keeps its own delay and the loop count is the source’s. To change the speed, use Change GIF speed, which rewrites only the delays.

Why is no size offered for my GIF

Either it is already under the smallest size offered, or even the last step — 25% of the width, 32 colours — leaves it larger than every size below its own. The page says which, with the smallest it came to. A shorter GIF, cut from the video again, is the way under that.

Is the GIF uploaded

No. The browser reads it from your disk and the new file is written on this page. There is no upload endpoint on this site, so there is nowhere for the file to go.

Related specs

4