GIF speed changer
Speed a GIF up or slow it down without re-recording it.
Drop your file here
Processed securely and deleted within the hour.
Two genuinely different methods
Changing the timing keeps every single frame and rewrites how long each one is shown. Nothing is lost, nothing is re-encoded, and the animation is exactly the same pictures played at a different rate. This is what you want almost always.
Resampling holds the frame rate constant and drops or duplicates frames instead. Speeding up by 2× throws away every other frame; slowing down duplicates them. It produces a smaller file when speeding up, and it is the only way to go faster than the format's own floor.
The distinction matters and most tools do not offer it. This one previously used the obvious implementation for the timing mode, which quietly turned a ten-frame animation into seven — a mode labelled "keeps every frame" has to actually keep every frame, so it is now done a different way.
The 0.02 second floor
Here is the limit nobody mentions. GIF delays are stored in hundredths of a second, and browsers have long treated a delay below two hundredths as "unspecified" and substituted a tenth of a second instead. So an animation sped up past that point does not play faster — it plays ten times slower, which is a genuinely confusing failure.
Rather than walk into that, delays are clamped at two hundredths and the result tells you how many frames hit the floor. If you need it faster than that, resampling is the answer: dropping frames speeds up playback without needing a shorter delay.
Slowing down
Slowing down is the easy direction — there is no ceiling on how long a frame may be shown. Past about half a second per frame it stops reading as an animation and starts reading as a slideshow, which the result will mention, but nothing breaks.
Why the file size barely moves in timing mode
Because the pictures are identical. Only the delay values change, and there are two bytes of them per frame. Speeding a GIF up does not make it smaller unless you drop frames — which is another reason to reach for resampling when size is the goal.
Getting it right first time
If you are unsure what speed you want, the frame extractor will tell you the current delays, which makes the arithmetic obvious: frames at 100 ms are running at 10 fps, so 2× gives you 20.
Common questions
Which method should I use?
Timing, unless you are speeding up past about 5× or you want a smaller file. Timing keeps every frame; resampling drops them.
Why will it not go faster than a certain point?
GIF delays are hundredths of a second, and browsers replace anything under 0.02 s with 0.1 s — so pushing past it makes the animation play slower, not faster. Use resampling instead.
Does speeding up make the file smaller?
Not in timing mode — the frames are unchanged and only the delays differ. Resampling drops frames and does make it smaller.
Can I slow it down as much as I like?
Effectively yes. There is no ceiling on frame delay, though past about half a second per frame it reads as a slideshow.
Will the quality change?
Not in timing mode — the frames are untouched. Resampling re-encodes, so the palette is rebuilt.
How do I know the current speed?
Run it through the frame extractor: each filename carries that frame\u2019s delay. 100 ms per frame is 10 fps.