Image converter
Going from WebP to JPG almost always means a larger file at the same or slightly worse visible quality, because you are moving from newer compression to older compression. That is an acceptable trade when the alternative is a file you cannot use at all, but there is no quality to be gained here. If whatever you are feeding the image to does support WebP, keep the WebP.
WebP files can carry an alpha channel and JPG cannot, so any transparent area has to be filled with a solid colour. This converter paints white behind the image before encoding. If your WebP is a cut-out graphic and you need to keep the transparency, convert it to PNG instead — that keeps the alpha channel intact.
A WebP saved from a website has already been compressed lossily, and encoding it as JPG compresses it again. On photographs this is usually unobjectionable. On screenshots with text or flat-colour graphics, JPEG tends to add visible fuzz around sharp edges, and PNG is the better destination for that kind of image.
Convert PNG to JPG in your browser. Transparent areas are flattened to solid white before encoding — here is exactly why, and what to use instead.
Convert WebP to PNG in your browser and keep transparency when the source has alpha. No upload, no account — output size shown before download.
Convert BMP to JPG in your browser with a quality slider. BMP is uncompressed; JPG shrinks photos for email and forms. Nothing is uploaded.
Rasterize SVG to JPG in your browser. Pick JPG quality and a background colour for transparent SVGs. No upload — vectors render on a canvas.
Convert ICO to JPG in your browser. Uses the largest icon frame your file provides. Pick quality and background colour — no upload.
Convert AVIF to JPG in your browser when an app rejects AVIF. Quality slider and background colour for alpha — decode depends on your browser.