What it is
GIF dates from 1987. Each frame stores up to 256 colours from a palette, compressed without loss by LZW, and a file can hold many frames with a display time for each — which is why, decades later, it is still what people mean by an animated picture.
The palette is the catch. A photograph has hundreds of thousands of distinct colours; squeezed into 256, smooth areas break into visible steps (posterisation). Dithering scatters nearby palette colours to fake the missing ones, trading the steps for grain. Transparency is a single palette entry, so a pixel is either fully see-through or fully solid.
Where it opens
The rows below are about software a file will actually be handed to, not about a specification. A format is supported when the person you sent it to can open it.
| Where | What happens |
|---|---|
| Every browser | Opens and animates GIF, and has for decades. |
| Windows and macOS viewers | Open GIF with nothing installed; the built-in viewers play animations. |
| Chat apps | Accept GIFs, though many turn an animated GIF into a short video when it is sent. |
| Displays in most clients; some desktop versions of Outlook show only the first frame of an animation. | |
| Photographs | Technically fine, practically poor: 256 colours band skies and skin, and the file is usually several times a JPEG's size. |
What it costs to write
Browsers cannot write GIF from a page, so this site carries its own GIF writer: each frame gets a palette of up to 256 colours chosen by median cut, optional Floyd–Steinberg dithering, then LZW compression, all in a background worker. The page prints how long it took on your device.
Where it goes wrong
- 256 colours per frame. A photograph bands; dithering hides the steps behind visible grain and makes the file larger.
- Transparency is on or off per pixel, so soft edges against a transparent background turn jagged or keep a halo of the colour they were drawn on.
- Animations grow fast: every frame is a full picture, compressed only with LZW. A few seconds of video as GIF can run to megabytes.
- Browsers slow down very short frame delays (10 ms or less) to about 100 ms, so an animation meant to be fast can play slowly.
When this is the right answer
GIF is right when the place you are posting asks for a GIF — a reaction animation, a forum signature, an old content system — or for small flat graphics with few colours. For a still photograph it is the wrong format: JPEG or WebP is a fraction of the size and keeps every colour, and PNG keeps a graphic exactly.
To take frames out of a GIF, GIF to JPG on this site lists every frame and saves any of them. To make one, JPG to GIF writes a still or animated GIF on your device with the timing you choose.
Questions about GIF
Why does my photo look blotchy as a GIF?
Is GIF lossless?
Why are animated GIFs so large?
Do GIFs support transparency?
How do I make a GIF from photos?
Encoding happens on this machine; the file stays where it is.