Is GIF a lossless or lossy image format?

GIF is a lossless image format because its LZW compression preserves the encoded pixel data without discarding image information.

Lossless compression reduces file size while allowing the original compressed image data to be recovered exactly. This makes GIF useful for simple graphics with flat colors, sharp edges, logos, icons, and limited-color illustrations. It does not mean every GIF looks high-quality: the format’s palette is normally limited to 256 colors, which can make photographs appear banded or dithered.

GIF’s compression method is Lempel–Ziv–Welch, or LZW. The method replaces repeated sequences with shorter codes rather than removing visual detail. By contrast, JPEG compression is typically lossy: it achieves smaller files by discarding some image information.

Animated GIFs remain lossless at the frame-data level, but converting a video or full-color image into GIF may visibly reduce quality because of the limited palette and frame sampling. The format can also become inefficient for photographic content, where PNG, WebP, or video formats may be more suitable.