How to make a GIF smaller: what each setting costs, measured on one clip

Why your GIF is so big

GIF was designed in 1987. Every frame is stored as a bitmap with at most 256 colours, and its compression only finds runs of identical pixels. Video formats store the difference between frames and throw away detail you can’t see; GIF does neither. So the size is close to:

pixels per frame × number of frames × how noisy the pixels are

Noise is the part people miss. To fake more than 256 colours, encoders dither: they scatter pixels of nearby palette colours to blend them. Your eye reads it as a smooth gradient; the compressor reads it as random data it can’t shrink. That’s why a GIF of a clean gradient can be bigger than one of a busy photo.

One clip, measured 23 ways

All numbers below are real file sizes from a 10-second, 1080p clip of Big Buck Bunny (Blender Foundation, CC BY 3.0), encoded on 16 Sep 2026 with the same two-pass palette pipeline Simple GIF Maker uses. Unless a row says otherwise: 256 colours, Sierra dithering, one palette for the whole clip.

Width and frame rate

Width	10 fps	15 fps	24 fps
320 px	4.2 MB	5.8 MB	8.4 MB
480 px	9.8 MB	13.6 MB	19.8 MB
640 px	17.8 MB	25.1 MB	36.6 MB
800 px	28.2 MB	40.0 MB	58.8 MB
960 px	41.0 MB	58.4 MB	86.3 MB

Width is the big lever because pixels scale with its square: halving the width (960 → 480) cut the file to about a quarter (58.4 → 13.6 MB at 15 fps). Frame rate is close to linear: 24 → 15 fps saved about a third; 15 → 10 fps saved another quarter.

A frame of the Big Buck Bunny clip at 800 pixels wide: the rabbit's fur and the grass are sharply detailed — The same frame at 800 px and 320 px, both shown at the same display size. Width is the setting that changes the file most, and the one you notice most.

The same frame at 320 pixels wide: the scene is recognisable but fine fur and grass detail are gone — The same frame at 800 px and 320 px, both shown at the same display size. Width is the setting that changes the file most, and the one you notice most.

Colours

At 480 px and 15 fps:

Colours	Size	Saving vs 256
256	13.6 MB
128	10.9 MB	20%
64	8.4 MB	38%
32	6.5 MB	52%

Colours save less than you’d expect because dithering fills the gaps with noise, and noise is what the compressor can’t shrink. Here’s what each step looks like, cropped from the same frame and enlarged 3×:

A 3x enlarged crop of tree roots and moss from the 256-colour GIF: smooth shading with fine dithering — 256 colours against 64. At 64 the dithering is visible in the roots and the darker moss, but the frame still reads well at normal size.

The same crop at 64 colours: the roots and moss show visible dither speckle and some flattened shading — 256 colours against 64. At 64 the dithering is visible in the roots and the darker moss, but the frame still reads well at normal size.

The same 3x enlarged crop at 32 colours: the tree roots have collapsed into flat patches of grey-green and the moss shading is posterised — 32 colours. The roots have lost their shading entirely. This is the point where most footage stops being worth it.

Dithering

At 480 px, 15 fps, 256 colours:

Dithering	Size
Sierra (the app’s default)	13.6 MB
Floyd–Steinberg	13.2 MB
Bayer, scale 3	11.7 MB
None	11.6 MB

Turning dithering off saves about 15% on this footage, and Bayer (an ordered pattern instead of scattered error) saves nearly as much. The cost is banding in gradients: skies, shadows, and soft lighting turn into visible steps. On flat interface captures there are no gradients to protect, so dithering off is the right call for UI GIFs; on video, keep Sierra unless you’re desperate. The palettes and dithering page has enlarged crops of each mode.

Length

At 480 px, 15 fps, 256 colours: 10 seconds is 13.6 MB, 5 seconds is 6.8 MB, 3 seconds is 4.1 MB. Length is the only lever that costs nothing in quality. Trim first, on the app’s timeline.

The one-step way

In Simple GIF Maker you type the size and it does all of the above for you: it encodes real GIFs and adjusts width, frame rate and colours until one fits, then shows you the trade-off line and a preview that is the encoded file. Lock Keep resolution if width is the thing you mind losing, or Keep fps for smooth motion, and it works around the lock.

Simple GIF Maker after a size-target export: the preview shows the smaller result and the trade-off line reads '960 to 554px wide, 15 to 11 fps, 256 to 128 colors, 8.17 MB' — A size-target result in the app. The line tells you what it traded, and the preview is the real file.

Shrinking a GIF you already have

If you only have the GIF, not the source video, the app takes GIF as input and applies the same trades. We fed it the 86.3 MB 960 px / 24 fps GIF from the table above and asked for 8 MB, then 4 MB. Real runs on an 8-core desktop:

Target	What the app reported	Result	Time
8 MB	`960 -> 442px wide, 24 -> 12 fps, 256 -> 80 colors -> 6.79 MB (target 8.00 MB)`	6.79 MB	26 s
4 MB	`960 -> 352px wide, 24 -> 10 fps, 256 -> 48 colors -> 3.06 MB (target 4.00 MB)`	3.06 MB	22 s

Re-encoding a GIF stacks two rounds of palette reduction, so a GIF made from the original video at the same settings looks a little better. Use the source video when you have it; the app opens MP4, MOV, MKV, WebM, AVI and more. One-time purchase on Steam, Windows and SteamOS/Linux.

Get Simple GIF Maker on Steam