Sources
ffmpeg lavfi gradients, mandelbrot, and testsrc2, each 5s long.
Original benchmark data
GIF vs MP4 vs WebP
Three matching test clips compare file size, measured SSIM, transparency, audio, and web playback behavior.
Controlled test settings
480×270
15fps
5s
ffmpeg 8.0.1
Same source, three outputs
File sizes come directly from the encoded outputs and are shown in KB. Higher SSIM means closer to the source video.
File size (KB)
| Test clip | GIF | MP4(H.264) | WebP |
|---|---|---|---|
| Low motion (gradients) | 2958 | 39 | 11 |
| High motion (mandelbrot) | 5132 | 423 | 915 |
| Detailed pattern (testsrc2) | 1248 | 205 | 463 |
Quality SSIM (higher is closer to source)
| Test clip | GIF | MP4 | WebP |
|---|---|---|---|
| Low motion | 0.872 | 0.998 | N/A |
| High motion | 0.942 | 0.988 | N/A |
| Detailed pattern | 0.967 | 0.994 | N/A |
Animated WebP SSIM was not measured, so it is marked N/A and no quality claim is inferred from it.
What the data directly supports
GIF is 6-75× the size of MP4 and 3-270× the size of WebP.
Across all three clips, GIF has lower SSIM than MP4 while producing a larger file.
MP4(H.264) delivers both smaller files and higher SSIM in this test.
WebP is smallest on the low-motion test at 11 KB; MP4 is smaller on the other two clips.
Method and reproducibility boundary
These results use standard synthetic clips. Real footage may produce a different ranking or a different gap.
Controlled input
Every source was normalized to 480×270 at 15fps before encoding into the three formats.
Encoding
GIF used two-pass palettegen/paletteuse with bayer dither; MP4 used H.264 crf23; animated WebP used q75.
Quality measurement
GIF and MP4 were measured against the source with SSIM. WebP was not measured and is recorded as N/A.
Format references: MDN image format guide / MDN autoplay guide
The formats do different jobs
GIF and WebP are image formats, while MP4 is a media container. Their embedding model changes autoplay, controls, and platform acceptance.
| Capability | GIF | MP4(H.264) | WebP |
|---|---|---|---|
| Color | 256-color indexed palette | Full-color video | Full color |
| Transparency | 1-bit: fully transparent or opaque | None in H.264 MP4 | Alpha transparency |
| Motion | Native image animation | Video playback | Native image animation |
| Audio | No | Yes | No |
| Inline autoplay | Direct image embed; generally starts automatically | Needs a video element or player; autoplay is policy-dependent and commonly requires muted and playsInline | Direct image embed in modern browsers; older platform support is less consistent than GIF |
| Looping | Animation loop metadata | Set by the video element or player | Animation loop metadata |
| Size and quality in this test | Largest in every clip; lower SSIM than MP4 | Smaller than GIF with higher SSIM in every clip | Smallest for low motion; SSIM not measured |
How to choose
No format wins every destination. Encoding results and embedding behavior belong in the same decision.
Prefer MP4 when video is accepted
When the destination accepts video and size plus fidelity matter, this benchmark supports H.264 MP4. It needs a video element or platform player, and audible autoplay remains subject to browser policy.
Consider WebP for transparency
Animated WebP combines full color with alpha and produced the smallest low-motion file here. It is a middle ground between image-style embedding and modern compression, though older platform support is less consistent than GIF.
Use GIF when frictionless sharing wins
GIF is bigger and blurrier in these tests because of its 256-color palette and weaker LZW compression. Its lasting value is image-like embedding, automatic looping, and no player requirement across familiar platforms.
Apply the result to your file
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Frequently asked questions
Is MP4 always smaller than GIF?
Three clips cannot establish a universal rule. In this controlled test, however, MP4 is smaller than GIF and has higher SSIM on every clip.
Is WebP always the smallest?
No. WebP is smallest on the low-motion test at 11 KB, while MP4 is smaller on the high-motion and detailed-pattern tests.
Why can GIF show banding or dithering?
Each GIF frame uses an indexed palette of up to 256 colors. Full-color video must be quantized and dithered, so gradients and complex scenes are more likely to show artifacts.
Why is WebP SSIM listed as N/A?
The original benchmark did not measure WebP SSIM. This page does not calculate, estimate, or add any other unmeasured quality metric.