Lossless vs Lossy Image Compression, Explained

Every image format makes one fundamental choice: keep every pixel exactly, or throw some away to save space. That choice is the difference between lossless and lossy.

Lossless

Lossless formats (PNG, TIFF, BMP, lossless WebP) reconstruct the original image pixel-for-pixel. Perfect for logos, screenshots, line art, and anything with sharp edges or text. The cost is file size — a lossless photo is large.

Lossy

Lossy formats (JPEG, AVIF, lossy WebP) discard detail the eye is unlikely to notice. This is ideal for photographs, where small imperfections are invisible, and produces dramatically smaller files. It is a poor choice for crisp graphics, where it introduces visible "ringing" around edges.

The rule of thumb

Photographs → lossy (JPEG, WebP, AVIF). Graphics, logos, screenshots, transparency → lossless (PNG). When in doubt, try both and compare file size against quality. You can convert in either direction in seconds.