Images · 2 min read ·
WebP vs PNG vs JPG: which one should you use?
A practical cheat sheet for picking an image format — and why converting in the browser keeps your files private.
Choosing an image format is a trade-off between file size, quality and transparency. Three formats cover almost every case on the web.
Quick rules
Photos: WebP, or JPG when an old system only accepts JPG. Logos, icons, UI and screenshots: PNG or lossless WebP, because they keep sharp edges and transparency. Favicons: ICO plus a PNG. AVIF is usually smaller still, but it takes longer to encode.
Why the same photo comes out smaller as WebP
JPG and lossy WebP both throw away detail the eye barely notices; WebP does it more efficiently, so a photo at similar quality is typically noticeably smaller. PNG is lossless — perfect for screenshots, wasteful for photos.
Why local conversion matters
The 4Dev image converter runs entirely in your browser: the picture is decoded and re-encoded on your device and never uploaded. It reads PNG, JPG, WebP, GIF, HEIC, AVIF, TIFF and more, and it can resize while it converts.