GIF

Graphics Interchange Format

image/gif Released 1987 · by CompuServe

GIF (Graphics Interchange Format) is a widely supported bitmap image format introduced by CompuServe in 1987. It uses lossless LZW compression and is most famous for its widespread use in short, looping web animations, despite its limitation to a 256-color palette.

Web Transparency Animation Progressive Production Ready

Technical Specifications

MIME Type

image/gif

Extensions

.gif

Container

GIF

Compression

Lossless (LZW)

Algorithms

LZW (Lempel-Ziv-Welch)

Color Depth

1-bit, 4-bit, 8-bit (Indexed)

Metadata

XMP ICC

Capabilities

Transparency

Animation

Progressive Loading

Alpha Channel

HDR Support

Official Specification

Magic Bytes & HTTP Headers

File Signature (Magic Bytes)

47 49 46 38 39 61

ASCII: GIF89a

HTTP Headers

Content-Type: image/gif

HTML Accept Attribute

accept="image/gif, .gif"

Browser Support Matrix

Browser	Status	Min Version
Chrome	Supported	All
Firefox	Supported	All
Safari	Supported	All
Edge	Supported	All
Internet Explorer	Supported	Legacy

Advantages & Limitations

Advantages

Universal support across all web browsers, operating systems, and messaging apps
Supports basic frame-by-frame animation out of the box
Lossless compression is highly effective for simple, flat-color graphics like logos or pixel art

Limitations

Limited to 256 colors per frame, resulting in poor quality for complex gradients and photographs
Animations produce massive file sizes compared to modern formats like MP4, WebP, or AVIF
1-bit transparency limits edge blending on non-uniform backgrounds

Developer Code Snippets

import imghdr
print(imghdr.what('animation.gif')) # Outputs 'gif'

const FileType = require('file-type');
const type = await FileType.fromFile('animation.gif');
console.log(type.mime); // image/gif

import "net/http"

mimeType := http.DetectContentType(fileBytes)
fmt.Println(mimeType) // image/gif

$mime = mime_content_type('animation.gif');
echo $mime; // image/gif

File Detection Steps

How to programmatically detect a image/gif file by reading its raw bytes:

1 Check first 6 bytes for the 'GIF87a' (47 49 46 38 37 61) or 'GIF89a' (47 49 46 38 39 61) string

Software Support

A

Adobe Photoshop

GIMP

ImageMagick

E

EZGIF

A

Adobe After Effects

Conversion Tools

Convert GIF to →

GIF WebP

Share & Embed

Markdown Badge

[![GIF Format](https://freewebptojpg.com/mime/image/gif/badge.svg)](https://freewebptojpg.com/mime/image/gif)

Interactive iframe Widget

<iframe src="https://freewebptojpg.com/mime/image/gif/embed" width="100%" height="280" style="border:1px solid #cbd5e1;border-radius:8px;" title="GIF Specs"></iframe>

JSON API

All data on this page is available as a free, open JSON API. Use it in your project, documentation, or tooling.

GET https://freewebptojpg.com/mime/image/gif.json Open JSON

Free to use

No auth required

CORS enabled

Use from any domain

Cached 24h

Cache-Control headers set

Frequently Asked Questions

What is the magic byte for GIF?

GIF files begin with either 'GIF87a' or 'GIF89a'. In hex, this signature corresponds to 47 49 46 38 37 61 or 47 49 46 38 39 61 at the very start of the file.

Does GIF support transparency?

Yes, but only 1-bit transparency (introduced in GIF89a). This means a pixel is either fully transparent or fully opaque. It lacks the partial transparency (alpha channel) found in PNG or WebP, which often leads to jagged, un-aliased edges.

Why do GIFs sometimes have poor color quality?

The standard GIF format is restricted to a maximum of 256 colors (8-bit) per frame. When converting complex images like photographs to GIF, the software must use color quantization and dithering, which often causes visible banding and graininess.