How to Convert JPG or PNG to WebP

WebP files are smaller than JPG or PNG at equivalent visual quality, and every modern browser has displayed it without issue for years now. That combination (real savings, zero compatibility downside) makes converting to WebP one of the easiest, highest-payoff changes you can make to a batch of images.

Converting JPG to WebP

This is the most common case: photos, product shots, anything headed for a website. JPG and WebP are both lossy formats by default, so converting between them is a straightforward swap — at the same visual quality, WebP files typically come out 25-35% lighter than the equivalent JPG. For a page full of photos, that difference adds up to a genuinely faster load.

Converting PNG to WebP

A different case: screenshots, logos, icons, or any graphic with flat colors, sharp text, or a transparent background. Here the move is to keep WebP in lossless mode — it preserves transparency and exact pixel detail just like PNG, but still comes out smaller, since WebP's lossless compression is more efficient than PNG's for most images. You get the same fidelity at a lighter file size.

Will you lose quality doing this?

Converting a JPG (already lossy) into a lossy WebP is technically a second lossy pass, so a small amount of additional degradation is unavoidable in the strictest sense. In practice, at a reasonable quality setting (80+), it's not something you'll notice at normal viewing size. It only becomes visible if you convert back and forth repeatedly or push the quality very low.

If you're converting a PNG to lossless WebP, there's no quality loss at all — every pixel comes through exactly as it was, just re-encoded more efficiently.

How to actually do it

Drop a JPG or PNG (or a whole folder of them) into img-compress, pick WebP as the output format, and download: no account, no upload, nothing that leaves your device. A full batch works the same way as a single file — process the whole set and download it as a ZIP instead of running each image through a converter one at a time.

For the broader tradeoffs between formats, including where AVIF fits in, see WebP vs JPG vs PNG vs AVIF. And if image weight is what's slowing your site down in the first place, how image size affects website speed covers where WebP fits into the bigger picture.