GIF was created in 1987. It supports animation, which no other widely-supported image format did at the time. This monopoly on animated images made GIF the default format for short animations on the web for 30 years. But technically, GIF is a terrible animation format by modern standards.
The technical comparison
GIF: - Maximum 256 colors per frame - No audio support - Large file sizes (no temporal compression) - Plays automatically, loops automatically - Supported everywhere (email, chat, social media, forums) - No playback controls (no pause, no scrub)
MP4 (H.264): - Millions of colors (full color depth) - Audio support (optional) - Small file sizes (temporal + spatial compression) - Autoplay depends on the platform (most mute autoplay) - Supported on all modern browsers and devices - Playback controls available (pause, volume, fullscreen)
WEBM (VP9/AV1): - Millions of colors - Audio support (optional) - Smallest file sizes (more efficient than H.264) - Autoplay depends on the platform - Supported in Chrome, Firefox, Edge (not Safari until recently for VP9, AV1 support is still limited) - Playback controls available
File size comparison
For a 5-second clip at 480px width, 15fps: - GIF: 3-8 MB typical - MP4: 200-500 KB typical - WEBM: 150-400 KB typical
The MP4 is 10-20x smaller than the GIF at higher visual quality. The WEBM is even smaller.
When to use GIF
Despite its technical inferiority, GIF is the right choice in specific situations:
Email: Most email clients do not support embedded video. GIF is the only animation format that reliably plays inline in emails across Gmail, Outlook, Apple Mail, and others.
Chat applications: Slack, Discord, and Teams have dedicated GIF support with previews and autoplay. While they also accept MP4, the user experience for GIFs (inline preview, auto-loop, no play button) is better in chat contexts.
GitHub READMEs and issues: GIF is the standard for demonstrating UI interactions, bugs, and features in GitHub. MP4 works in some contexts but GIF is more reliably rendered.
Memes and reactions: The cultural expectation for short reaction animations is GIF format. Sending an MP4 as a reaction does not have the same feel.
When to use MP4
Social media posts: Instagram, TikTok, Twitter, and Facebook all prefer MP4. They re-encode uploads anyway, so starting with a high-quality MP4 produces the best result.
Web pages: Embedding a short looping video as an MP4 with the autoplay, muted, loop, and playsinline attributes produces the same visual effect as a GIF at a fraction of the file size. This is what most modern websites use for animated hero sections and product demos.
Tutorials and demos: When you need playback controls (pause, scrub, fullscreen), MP4 is the right choice.
When to use WEBM
Web pages where file size is critical: WEBM produces the smallest files for animated content. If you are embedding looping animations on a page that needs to load fast, WEBM with VP9 is the most efficient option.
The caveat is browser support. Safari's WEBM support has improved but is not universal across all Safari versions. For maximum compatibility, serve WEBM with an MP4 fallback. The MediaBrew GIF conversion tool handles the GIF case specifically; if you determine MP4 or WEBM is the better format for your use case, your source video is likely already in one of those formats.