Lossy vs Lossless Image Compression

When optimizing images, you will encounter two main types of compression: lossy and lossless. Knowing the difference is crucial for choosing the right tool.

Lossless Compression

What it is: Reduces file size by efficiently encoding the data without discarding any information. When decompressed, the image is mathematically identical to the original.

Pros: Zero loss of quality. Perfect for text, line art, medical imaging, and logos.

Cons: File size reduction is minimal compared to lossy compression.

Formats: PNG, GIF, RAW, WebP (Lossless).

Lossy Compression

What it is: Reduces file size by permanently discarding less important visual information based on human perception models.

Pros: Massive file size reduction (often 50-80% smaller). Perfect for photographs and complex web images.

Cons: Quality degrades with heavy compression. Once data is lost, it cannot be recovered.

Formats: JPG/JPEG, WebP (Lossy).

Which should you choose?

For most website photography and social media, lossy compression is the best choice because the file size savings heavily outweigh the barely-noticeable quality drop. Use our JPG Compressor for photos. If you are uploading a logo or a graphic with text, stick to PNG.