JPG to WebP Converter

This tool converts JPG (JPEG) images to WebP files in your browser. The reason to do it is size. WebP is the format Google introduced in 2010 and most websites now serve, because for the same picture at the same visual quality it is usually 25–50% smaller than a JPG. Smaller images mean faster pages, lighter email attachments and less storage, and every current browser reads WebP — Chrome, Edge, Firefox and Safari — so the risk of producing a file nobody can open is far lower than it was a few years ago.

Here is the trade-off, and it is worth stating plainly. JPG is already lossy, and WebP is lossy too, so this conversion is a second generation of compression on top of the first. The file is decoded to pixels and encoded again, and whatever the new encoder decides you will not notice is removed once and for all. At the default quality of 90 the extra loss is small and usually invisible in a photograph, but it is not nothing. The browser's canvas can only write lossy WebP — there is no lossless option here — so if you need every pixel exactly as the JPG has it, keep the JPG.

Transparency is not an issue in this direction. A JPG has no alpha channel at all, so there is nothing to lose, and the WebP comes out with exactly the solid background the JPG had: white stays white. There is no background colour to choose here, because there is nothing to fill in — that is the difference from converting a PNG to JPG, where transparency has to be flattened onto a colour.

What does not come across is the file's metadata. The EXIF data your camera wrote — the date, the camera model, the GPS location — is not copied, and neither is any embedded colour profile; colours are written as standard sRGB. The orientation tag is applied as the image is decoded, so a photo that looked sideways elsewhere comes out upright. Nothing leaves your device: the JPGs are read into your browser's memory, converted there and handed back as downloads, and you can confirm in the Network tab of your browser's developer tools that no request carries your file. Up to 50 files per batch, each up to 50 MB, downloadable individually or as a ZIP.

1. Each file's first bytes are checked for the JPEG signature FF D8 FF. .jpg, .jpeg, .jpe and .jfif are all the same format and all pass; anything else is rejected with a message naming what the file really is, because the bytes decide, never the extension. 2. The browser decodes the JPEG with createImageBitmap, which applies the EXIF orientation tag, so the image is stored upright. 3. The decoded pixels are drawn onto a canvas of the same width and height — no resizing, no background painted, because a JPG is fully opaque. 4. Quality (1–100) is validated and converted to the 0–1 scale canvas.toBlob takes. 90 out of 100 is the default, where the second-generation loss is hard to see. 5. The canvas is encoded with canvas.toBlob("image/webp", quality) — lossy WebP — and the file keeps its original name with the extension changed to .webp. The size before and after is shown for every file.