How you end up with WebP files
Most WebP files on a typical computer were never chosen by their owner. Websites serve WebP because it loads faster, so right-clicking a product photo, a recipe picture or a news image and choosing "Save image as" often stores a .webp file even when the page looks like it shows ordinary photos. Some messengers and phone keyboards also save stickers and shared images as WebP.
Support has improved a lot since Google introduced the format in 2010, but gaps remain. Older photo viewers and editors, some versions of Microsoft Office, print shop upload pages, marketplace listing forms, and many document and visa portals accept only JPG or PNG. JPG remains the format that every device, program and form understands.
Which kind of WebP you have
WebP is really three formats under one extension, and each converts differently:
- Lossy WebP is the common case for photos. It is already compressed, so converting it to JPG cannot restore detail; it only repackages what is there. This is the type JPG suits best.
- Lossless WebP is used for graphics, logos and screenshots, often with transparency. Converting these to JPG adds compression artefacts around sharp edges and text. For such images WebP to PNG keeps every pixel exactly.
- Animated WebP works like a GIF. Only the first frame is converted, since JPG holds a single still image.
If you are not sure, look at the picture: a photo of a real scene is almost certainly lossy WebP; a flat-coloured icon or a sticker with a transparent background is likely lossless.
What the converter changes
Your browser decodes the WebP, draws it onto a canvas filled with white, and encodes the canvas as JPG at the quality you set, in a background worker when the browser supports one. Nothing is uploaded.
- Size in pixels stays exactly the same.
- Transparent areas turn white, because JPG has no transparency and this converter always uses a white background. Semi-transparent edges are blended with white too, which looks right on light pages but leaves a pale fringe on a dark one.
- Metadata such as EXIF data that a few WebP files carry is not copied.
- Colour is output in standard sRGB, which is what virtually all web WebP images already use.
Matching the quality to the source
The slider runs from 10% to 100% and starts at 85%. Because a web WebP has usually been compressed fairly hard already, the aim is to preserve what is there rather than to compress further.
- 85% is right for most saved web photos. The JPG looks the same as the WebP at normal size.
- 90–95% if you will print the image, crop into a small part of it, or edit and save it again. These steps magnify any artefacts from the conversion.
- 75% when a form demands a small file and the image is only shown at small size, such as a profile picture or a listing thumbnail.
Expect the JPG to be larger than the WebP, commonly by 30 percent to double. That is the efficiency gap between the two formats, not a sign of anything wrong. If the result exceeds an upload limit, reduce it with Compress JPG, which lets you aim for a smaller size directly.
Practical cases and pitfalls
- Printing a web image. Web images are often only 800 to 1200 px wide, enough for a print of about 7 to 10 cm at 300 dpi. Converting to JPG fixes the format, but cannot add resolution; look for a larger original if you need a bigger print.
- Uploading to a listing or form. Many sites check the file extension. A renamed
.webpfile still contains WebP data and is usually rejected or shown broken; a real conversion avoids that. - Batch downloads from a website. Drop the whole set at once. Each file can be up to 50 MB, the list shows old and new sizes, and everything can be downloaded as one ZIP with the original file names and a
.jpgextension. - Images that fail to load. A partly downloaded or damaged file cannot be decoded. Open it in a browser tab first; if it does not display there, save it from the website again.