How image compression works
Compression removes visual information the human eye barely notices. Lossy formats like JPG, WebP and AVIF discard fine detail in exchange for dramatically smaller files, while lossless PNG compression only reorganises data so pixels stay identical.
Aimager decodes your image, re-encodes it with a modern encoder, and validates the result before you download. You control the quality slider, or Smart Optimize balances size and clarity for you.
When to compress instead of convert
Compress when you want to keep the same format but need a smaller file - for example emailing a 6 MB photo or speeding up a web page. If you also want a more efficient format, combine compression with a conversion to WebP or AVIF for the biggest savings.