Transparency and image fidelity
Both PNG and WebP can store alpha transparency. PNG stores pixel values losslessly, which suits crisp interface elements, screenshots, diagrams and files that will be edited again. Lossy WebP can reduce image weight but may soften edges or alter small details.
WebP also supports lossless coding, though browser canvas quality controls typically request lossy WebP output. Check the exact tool or encoder mode if byte-for-byte or pixel-exact output matters.
Choosing for a website
Use PNG when exact appearance and compatibility are the priority, especially for a small number of graphics where the file size is acceptable. Try WebP for photographic images or mixed-content artwork where bandwidth matters; compare transparency edges and text carefully.
A PNG screenshot can compress differently from a natural photograph. File extension alone is not a promise about size - dimensions, color variation and encoder settings matter too.
Frequently asked questions
Can WebP keep a transparent background?
Yes. WebP supports alpha transparency, as does PNG.