Image Converter: WebP, JPG and PNG

What happens when you convert a file

Your browser already knows how to read WebP, JPG and PNG, so the converter uses it. Each file is decoded into raw pixels, drawn onto an off-screen canvas, and saved again in the format you picked. Nothing is sent over the network, which is why it also works offline once the page has loaded. Files are converted one at a time, and the results are kept in memory only, so changing the JPG quality or background colour converts them again straight away without asking you to choose the files a second time. When you download several files as a ZIP, the archive is also built in your browser.

Because the picture is redrawn rather than edited in place, the output is a new file. Its pixels are what your browser decoded from the original, and photos keep their correct orientation. Metadata such as camera settings, timestamps and GPS location is not copied across, which is useful if you were about to share a photo and would rather not include where it was taken.

PNG, JPG and WebP: which to use

PNG is lossless: every pixel is stored exactly, and transparency is supported. That makes it the right choice for screenshots, logos, diagrams and anything with sharp text, and for images you will edit repeatedly. The cost is file size, particularly for photographs. JPG is lossy: it throws away detail the eye is unlikely to miss to make photos much smaller, but it cannot store transparency, and every time you edit and re-save a JPG it loses a little more. WebP can do both lossy and lossless compression, and supports transparency, so web developers use it to make pages load faster. All current browsers display it, but some desktop editors, printers, document tools and older apps still refuse it, which is the usual reason people need to convert it.

What each conversion does and does not do

WebP to PNG keeps transparency and does not lose anything further, but the PNG is usually larger, because WebP files are often saved with lossy compression and PNG stores every pixel. Converting does not make the picture worse.

JPG to PNG gives you a lossless copy. That is useful if you are going to edit and re-save the image, or if a site or print service insists on PNG. It cannot bring back detail that JPG compression already removed, and the file will be several times larger for a photo. The background does not become transparent.

PNG to JPG makes files smaller, often dramatically for photos. Because JPG has no transparency, any transparent area is filled with the background colour you choose, white by default. The quality slider trades size against fidelity: values around 80 to 90 suit most photos, and lower values give smaller files with more visible artefacts around edges. For screenshots and text, PNG can look cleaner at a similar size, so compare the result before replacing the original.

Limits to know about

The converter handles WebP, JPG and PNG. HEIC photos from iPhones are not supported at the moment. Animated WebP files come out as a still of the first frame. Very large images can fail on devices with little memory, in which case the tool shows an error for that file and carries on with the others. Embedded colour profiles and metadata are not carried into the output, and the result is drawn in your browser's standard colour space, which is fine for ordinary use but not for professional colour-managed print work.