GIF File Format (.gif)

A GIF file stores one or more indexed-color images, each limited to a palette of at most 256 colors, in a container CompuServe designed in 1987 that became the format the web uses for short looping animations.

.gifImage Files

GIF at a glance#

Full name	CompuServe graphics interchange format
File extension	.gif
Category	Image Files
Developer	CompuServe
First released	1987
MIME types	image/gif
Compression	Varies from file to file
Specification	GIF89a Specification
FileFlip support	FileFlip reads and writes this format

What a .gif file can hold#

These are the things a GIF file either supports or does not, and they are what decides whether a conversion keeps everything or quietly drops something.

Transparency (alpha channel)	Yes
Animation	Yes
Lossless compression	Yes
Embedded metadata	No
Colour profiles	No
High dynamic range	No
Comments	Yes

Strengths and limitations of GIF#

What GIF does well

Animation and looping work in every browser and image viewer without a plugin
Single-color transparency lets an image sit on any background
LZW compression is lossless, so a flat-color image with 256 colors or fewer re-saves without further loss
No licensing cost or patent restriction since the underlying LZW patents expired in 2003 and 2004

Where GIF falls short

Capped at 256 colors per frame, which forces a photograph to be quantized and visibly banded or dithered
Transparency is all-or-nothing per pixel, with no partial or soft-edged transparency the way PNG or WebP support
Animated GIFs run several times larger than the same animation encoded as WebP or a video file
No audio track, so any sound has to come from a separate video format

Use GIF for short looping animations and simple graphics with flat colors, like reaction clips or icons, where universal playback matters more than file size.

Convert GIF to PNG or WebP when the image is a single still frame, since both hold more than 256 colors and compress a flat-color graphic to a smaller file; convert an animated GIF to WebP or MP4 when file size matters, since either can be a fraction of the size at the same frame count.

How to open a .gif file#

A .gif file opens in the programs below, grouped by the platform you are on. If you would rather not install anything, FileFlip converts GIF into a format your machine already opens, and it does it in the browser tab rather than on a server.

Platform	Programs that open it
Windows	Photos, Paint, Adobe Photoshop, IrfanView, GIMP
macOS	Preview, Photos, Adobe Photoshop, Affinity Photo
Linux	GIMP, Eye of GNOME, ImageMagick
iOS	Photos, Files
Android	Google Photos, Gallery
Web	FileFlip

GIF questions people ask#

Is GIF a lossy or lossless format?

The compression GIF itself performs is lossless: LZW compresses the pixel data without discarding anything. The loss happens a step earlier, when an image with more than 256 colors has to be quantized down to fit GIF's palette limit, which is a form of lossy conversion that occurs before compression even starts. A graphic that already has 256 colors or fewer, like a simple icon, converts to GIF with no loss at all.

Why is GIF limited to 256 colors?

GIF stores each pixel as an index into a color table of at most 256 entries, a design CompuServe chose in 1987 to keep files small on the modem speeds of the time. Each frame can carry its own local color table chosen from the full 24-bit RGB space, so a multi-frame GIF can technically show more than 256 colors overall, but any single frame is still capped at 256.

How do you pronounce GIF?

CompuServe engineer Steve Wilhite, who created the format, has said he intended it to be pronounced 'jif,' with a soft g, deliberately echoing the peanut butter brand of the same name. He said so publicly when accepting a Webby Award in 2013, which set off a large and still-unresolved argument online, and most dictionaries now list both the soft-g and hard-g pronunciations as acceptable.

Was GIF ever patent-encumbered?

Yes. GIF's LZW compression was covered by a patent Unisys held, and in December 1994 Unisys announced it would require licensing fees from software that read or wrote GIF files, which caused a public backlash and pushed the PNG format's creation as a patent-free alternative. The core US patent expired in June 2003 and the last international patents by mid-2004, so LZW and GIF have been free to use without a license since then.

Why do GIFs have no sound?

The GIF format only ever defines image data: a stream of one or more indexed-color frames plus timing and looping information. CompuServe never added an audio channel to either the 1987 or 1989 version of the spec, so a GIF with sound isn't possible; a video format like MP4 or WebM is needed for that.

Converting GIF files#

Every conversion runs inside your browser. The file is read from your disk, the work happens on your own machine, and nothing is uploaded. How FileFlip works names the engine behind each family and how to verify that for yourself.