Why WebP files appear
WebP is Google's image format, now used by most websites because it is roughly a quarter to a third smaller than JPEG for the same look. When you save an image from a web page, you often get a .webp file. Every current browser opens it, as do Windows 11, macOS and phones, but some older desktop software, printing kiosks, and upload forms still do not.
What you lose and keep
Converting to JPG decodes the WebP and re-encodes it with MozJPEG. At quality 85 the result looks the same, but the file is usually larger than the WebP, because JPEG is less efficient. Transparency is not possible in JPEG: transparent areas are filled with white. Animated WebPs become a still image of the first frame.
Quality setting
The WebP was already lossy. Re-encoding at a high quality (85–90) avoids adding visible artefacts on top. Lower quality only if you need a small file.
When to keep WebP
If the destination accepts WebP (most websites, social networks and modern apps do), keep it: it is smaller. Convert only for software or forms that refuse it. To go the other way, use JPG to WebP.
WebP and JPG compared
| Feature | WebP | JPG |
|---|---|---|
| Size for the same look | Smaller | Larger |
| Transparency | Yes | No (filled white) |
| Animation | Yes | No |
| Opens everywhere | Most modern apps | Everything |
Step by step
- Add your WebP files: choose them, drag them onto the page, or paste.
- Set the quality; 85 is a good default.
- Click Convert to JPG.
- Download each file, or all of them as a ZIP. File names stay the same with the new extension.
Without this tool
Open the WebP in Paint (Windows) and use Save as → JPEG, or open it in Preview (Mac) and use File → Export → JPEG. Both re-encode, like this tool, but one file at a time.
Troubleshooting
- A file shows an error. It may not really be WebP: files are sometimes renamed without being converted. The tool reads the file's contents, not its name, and says what it found.
- The converted file is larger. That is expected when going to a less efficient or lossless format; it is not a fault.
- Colours shift slightly. Wide-gamut originals are converted to standard sRGB, which every screen shows consistently.
Saving web images as JPG directly
Some browsers can save an image as JPG instead of WebP if you open it in a new tab and use a save-as option, and some websites serve JPG to older browsers. Converting here is simpler and works for any WebP you already have.
Private by design
The image never leaves your device. It is decoded in your browser, processed in a background worker by open-source codecs compiled to WebAssembly (MozJPEG, libwebp, libavif and OxiPNG, via the jsquash project, plus pica for resizing) and handed back as a download. There is no upload, no account and no server copy to delete. You can confirm it in your browser's developer tools: the Network tab shows the page's own files and the codec files loading, and nothing carrying your image. After the first visit the tools work offline.