JPG or WebP: choose for the destination

A useful format depends on where your image will be viewed, not just on the smallest number of bytes.

Begin with the actual use

For a photo on a modern website, WebP is a useful starting point because it supports both lossy compression and transparency. JPG remains a practical choice for systems that explicitly ask for JPEG, older workflows, print uploads and email services. Check the receiving service before converting.

Purow exports browser-encoded JPG or WebP. The result shows the actual format and byte size. If a browser cannot encode the requested format, the tool reports an error instead of naming a PNG file as WebP.

Compare quality as well as size

Try the same photo at quality 82 in both formats. Download both results and inspect fine textures, lettering and edges at the size people will actually see. Quality values are encoder settings; 82 does not mean 82 percent of the original detail.

Do not repeatedly compress an already compressed file. Begin each comparison with the original. A WebP or JPG output may be larger than the input, especially if the source is already efficient. Purow shows the size change even when it is an increase.

Transparency changes the choice

JPG cannot preserve transparent pixels. Purow composites them over white. Choose WebP or, in the resize and metadata tools, PNG if a transparent background is needed. Keep the original file until you have checked the download in its destination.