Convert WebP to JPG

Two lossy formats, one after the other

A lossy WebP is a VP8 video key frame: the colour was stored at a quarter of the resolution of the brightness and the detail was quantised in 4×4 blocks when the website made it. A JPEG does the same two things with a different grid — 8×8 blocks and its own chroma subsampling — so converting one into the other is two generations of loss on different grids. At quality 85 and up the second generation is below what the eye finds; the damage shows first in smooth gradients (sky, skin) as faint banding, and in text edges as a second ring.

The file usually gets bigger, and that is the conversion working. WebP exists because it stores a photograph in about two thirds of the bytes a JPEG needs for the same look, so a 240 KB download becomes a 350 KB JPG at a comparable quality — or a smaller, visibly worse one. Nothing is gained but compatibility, which is the whole reason to be here.

Metadata does not come across. A WebP from a website rarely has any, but one exported from a camera app can carry EXIF and an ICC colour profile; the pixels are converted in the standard sRGB space and the JPG is written without a profile, which is what every viewer assumes anyway.

When you want something else

If the program that refused the WebP is recent, try again before converting: Photoshop, GIMP, Affinity, Windows Photos, macOS Preview, every browser and most CMS upload forms have read WebP for years, and a form that rejects it is often checking the extension only. Renaming solves nothing — the bytes are still WebP — but updating the program often does.

For a folder, dwebp in.webp -o out.png followed by cjpeg or mozjpeg gives a better JPG at the same size than any browser encoder, and ImageMagick's magick mogrify -format jpg -quality 88 *.webp does a directory in one line.