What is GIF?
GIF is a lossless image format limited to a 256-colour palette per frame, with frame-based animation and one-bit transparency — obsolete for still images, still universal for short looping clips.
GIF at a glance
- MIME type
- image/gif
- File extensions
- .gif
- Specification
- CompuServe GIF89a, 1989
- Compression
- Lossless LZW, but applied after the image has been reduced to at most 256 colours.
- Transparency
- One bit only: a pixel is either fully transparent or fully opaque. No soft edges.
- Animation
- Yes — this is the only reason the format survives.
- Colour depth
- Maximum 256 colours per frame, chosen from a 24-bit palette.
- Metadata
- Comment and application extension blocks. No EXIF.
- Support
- Universal, including in places that block video playback such as many email clients and chat apps.
Strengths and weaknesses
- Plays automatically and silently everywhere, with no player controls.
- Works in email and messaging clients where video is blocked.
- Nothing to install, nothing to configure, no codec questions.
- The 256-colour limit visibly banded any real-world footage.
- File sizes are enormous — an MP4 of the same clip is routinely ten times smaller.
- Hard transparency edges look jagged over any background but the original one.
Why GIFs from video get so big
Video codecs only store what changed between frames. GIF stores each frame as a complete palettised image, so a five-second clip at 24 frames per second is 120 separate pictures with no shared compression between them.
The two levers that matter are frame rate and width. Dropping to 12 frames per second halves the frames, and a 480-pixel width is typically enough for a chat window. Both cut the file more than any amount of palette tuning.
When to use a video instead
If the clip will be embedded in a web page you control, MP4 or WebM is smaller, sharper and cheaper to serve. GIF earns its place only where autoplay video is unavailable — mailing lists, some chat clients, documentation platforms that strip video tags.
Working with GIF files
Convert to GIF
Formats people compare this with
- MP4MP4 is a container format, not a codec: it wraps video (usually H.264), audio (usually AAC) and metadata in one file, and it is the closest thing to a universally playable video file..
- WebPWebP is an image format developed by Google that offers both a lossy and a lossless mode, supports transparency and animation in either mode, and is typically 25–35% smaller than a JPG of comparable quality..
- PNGPNG is a lossless image format: it stores every pixel exactly as it was saved, supports a full alpha transparency channel, and never degrades no matter how many times the file is opened and saved again..