JPEG to WebP — Input checklist

Worked example

Pick a photo with real texture and gradients, and note how compressed the JPEG already is, since that decides if WebP saves bytes.

A good test file is a 1600 × 1067 px product or landscape photo with fabric, foliage or a sky gradient. Such pictures show the differences between formats clearly. A flat graphic or a tiny icon tells you little, since both formats handle them easily and the saving is a few hundred bytes.

The point most people miss is the starting quality. Chatcument re-encodes WebP at a fixed 92 percent. A JPEG that was already squeezed to about 70 percent, say a 480 KB file, may come out roughly the same size or even larger as a 92 percent WebP, because the new file is being encoded more generously than the old one.

Keep the conversion fair by working at identical pixel dimensions. The converter does not resize, so what goes in at 1600 × 1067 px comes out at the same size, which makes the byte comparison honest. If you want a smaller picture, resize once from the master photo before converting.

A practical check before committing a whole shoot: convert three typical images and compare the three sizes against the originals. A single batch takes up to 12 images and 48 MB, so you can trial a few and then load the rest.

JPEG photograph

WebP photograph

Already heavily compressed JPEGs may grow when re-encoded as WebP at the fixed 92 percent, so test before converting a whole set.