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Image File Formats for the Web
| GIF | JPEG/JPG | PNG | |
|---|---|---|---|
| Full name | Graphics Interchange Format | Joint Photographic Experts Group | Portable Network Graphics |
| File name extension | .gif | .jpeg or .jpg | .png |
| Browser support | excellent | excellent | IE6 problems |
| Animation | yes | no | no |
| Transparency* | yes (fixed) | no | yes (variable) |
| Compression** | lossless | lossy | lossless |
| Maximum no. of colors | 256 | millions | millions |
| Primary use | line art, logos, flat color | photographs, continous tone | line art, logos, flat color |
| Open standard | no, but patent expired | yes | yes |
| Intended output | screen | screen or print | screen or print |
* Transparency: With GIF, a pixel is either fully transparent or it's opaque. With PNG a pixel can be partially transparent (although some browsers don't properly support this PNG feature).
** Compression: Because of "lossy" compression, every time a JPEG is saved some information and quality is lost.