Why do my images save as WebP?
Because the site sent you a WebP. Every request a browser makes says which image formats it accepts, in its Accept header, and MDN’s table of default values shows image/webp in Chrome’s and Edge’s from version 121 and in Safari’s from macOS Big Sur. Google’s own WebP FAQ describes the other half: a server can look at that header and send WebP only to browsers that list it. So the same photo can be a JPG for one visitor and a WebP for you, and when you save it, you keep the WebP you were sent.
Renaming the file to .png does not change it: the bytes are still WebP, and programs that check them will still refuse it. Converting it, as this page does, writes a real PNG.
Does converting WebP to PNG lose quality?
PNG is lossless, so the PNG keeps exactly what your browser decoded from the WebP. We checked our test files pixel by pixel against the WebP as ImageMagick decodes it. In a photo and a screenshot, every pixel was identical (about 1.9 and 2.9 million). In two transparent logos, opacity matched everywhere, and about 11,800 and 13,300 of their partly transparent edge pixels shifted in colour, by at most 1.3 of 255 levels as they appear on screen, from how browsers store transparency while drawing. What PNG cannot do is undo the WebP’s own compression: if the WebP was saved lossy, its blur and artefacts are now in the PNG too. Colour profiles and other metadata in the WebP are not carried over.
Why is the PNG so much bigger than the WebP?
A lossy WebP throws detail away to stay small. PNG keeps every decoded pixel, including the noise the WebP’s compression added, and that costs space. In our tests every PNG was also saved with a transparency channel, even the photos, which adds to the size. Even against a lossless WebP, Google measured lossless WebP at 26% smaller than PNG. What we measured with this page, in Chrome on a desktop PC (sizes as the converter shows them, where 1 MB is 1,048,576 bytes):
| WebP | Size | As PNG | As JPG (quality 90) |
|---|---|---|---|
| Photo, 1,600 × 1,199, lossy | 415.7 KB | 4.0 MB | 639.6 KB |
| Photo, 3,992 × 2,992, lossy | 1.7 MB | 22.7 MB | 2.9 MB |
| Screenshot, 1,440 × 2,000, lossy | 121.1 KB | 940.3 KB | 260.9 KB |
| Logo with transparency, 800 × 322, lossless | 20.6 KB | 56.3 KB | not measured |
| Logo with transparency, 800 × 322, lossy | 6.7 KB | 81.3 KB | not measured |
Six files took 1.4 seconds in all. If you only need a format that an app will open and the image is a photo, JPG is far smaller; keep PNG for transparency and for graphics, logos and screenshots that must stay sharp.
WebP to PNG with a transparent background
WebP can store transparency, lossless or lossy, and the PNG keeps it: in our test the logo’s empty corners came out fully see-through. JPG has no transparency, so if you choose JPG, transparent areas are filled with the background colour you pick, white unless you change it. Converting cannot make a solid background transparent; for a plain background, use the transparent background maker on the PNG.
Animated WebP to PNG
A WebP can also be an animation. A PNG made here holds one picture: the browser hands the converter the first frame, and the converter says so next to the file. In our test, a three-frame animation gave a PNG of its first frame. To keep every frame, you need an animated format and a different tool; Google’s own dwebp command-line decoder does not handle animated WebP either.
Where WebP causes trouble
- Cricut Design Space lists JPG, BMP, PNG, GIF, HEIC, SVG and DXF as its upload types; WebP is not among them, so convert first.
- Windows: Microsoft’s free WebP Image Extension (Windows 10 build 17763 or later) lets Windows apps display WebP.
- Adobe Photoshop opens and saves WebP from version 23.2, for 8-bit RGB images.
- Browsers all display WebP now; Safari added it in version 14, in September 2020 (on a Mac, with macOS Big Sur or later).
Other ways to convert WebP to PNG
- Command line, with Google’s libwebp tools:
dwebp picture.webp -o picture.png(still images only). ImageMagick also reads and writes WebP. - Photoshop 23.2 or later: open the WebP and save it as PNG.
WebP itself is Google’s format, first released as a developer preview in September 2010, and it is now described in RFC 9649 (November 2024): lossy and lossless images, transparency and animation in one file type.
Why nothing is uploaded
Your browser decodes each WebP and draws it on this page; the files never leave your device. While we converted our test files, the only requests that left the page went to Google Analytics, for the page-view statistics described in the privacy policy. You can check: open your browser’s developer tools on the Network tab while converting.