format conversion
WebP to JPEG
The only conversion here where a lossy source that can carry transparency meets a format that cannot. Both of those cost something.
What actually changes
Transparency is flattened onto a colour
WebP carries an alpha channel and JPEG does not. Anything see-through is painted onto the colour set under “Behind transparency”, which starts white.
Source The converter’s Output panel — src/copy/en/convert.ts
Two lossy passes, one after the other
The JPEG is encoded from a lossless master decoded out of your WebP, so it is an approximation of an approximation. Whether the second pass is even smaller than the first is measured on your own file in the results table.
Source src/lib/convert.worker.ts — the master decode, per docs/v2/22
One quality dial serves both, on purpose
JPEG and WebP share a single quality setting here rather than getting one each. The three sizes in the results table are only comparable if they were asked for the same thing.
Source The quality control’s own note — src/copy/en/convert.ts
The short answer
Only if something insists on JPEG. If the WebP has a transparent background, this conversion will be the thing that put a white box behind your logo.
Convert it here
The converter takes your file, writes it as PNG, JPEG and WebP at the same pixel size, and shows you what each one weighs — measured on your file rather than on an average. It runs on the page using WebAssembly; the image never leaves your device.
Open the image converterThe other conversions
Every pair this tool can actually do. There are nine because it reads four formats and writes three, and a format cannot be converted to itself.
This page carries 3 facts and a source for each one. It is one of nine, generated from the same list the converter reads — so a page cannot exist here for a format the file picker would refuse.