You find the perfect image, download it, and then your application tells you the format is not supported. Or you try to upload it and the form says “invalid file type”. Nine times out of ten, the culprit is WebP, a format that looks like any other picture in your browser but does not travel well. The fix is quick once you know what is going on.
Why this happens
Modern browsers use WebP to make websites load faster, so many sites serve their pictures in that format. When you save such a picture, the file on your device is a .webp, even if it looked like an ordinary JPG on the page. The problem is that software outside the browser has been slower to adopt it. Office programs, older photo viewers, some printers, certain email clients and many upload forms were written before WebP was common, and they never learned to read it.
How to tell if a file is WebP
Look at the file extension. If it ends in .webp, that is the cause. Some systems hide extensions, so also check the file details: on a computer, right-click the file and open its properties or info panel. If the type says “WebP image”, you have found it. Another clue is where the picture came from: images saved from social media, shopping sites and search results are very often WebP.
The fastest fix: convert it
Converting WebP to a widely accepted format solves the problem for good.
- Use WebP to JPG for photographs and general uploads. JPG is accepted nearly everywhere.
- Use WebP to PNG for graphics, logos and pictures with transparency that you want to keep.
Add the file, convert it and download the result. The conversion runs in your browser, so nothing is uploaded.
Which one should you choose?
If the image is a photo, choose JPG, set the quality around 85 to 95 percent, and you will barely notice any loss. If the image has transparent areas, such as a logo with no background, choose PNG, because JPG fills transparent areas with a solid colour. If you are unsure and the destination is a form, JPG is the safest answer.
Other ways to avoid the problem
On some websites you can sometimes get a different version. Long-pressing an image on a phone may offer a “Save as JPG” option, depending on the browser. A screenshot is another workaround, although it lowers the quality and includes whatever else was on the screen. Opening the picture in a new tab and saving from there occasionally returns the original format. None of these is as dependable as converting the file.
An example from an application portal
Consider a visa application portal that keeps rejecting your photo. The picture looks normal and is the right size. The portal accepts only JPG, and the image you saved from a photo studio’s web gallery is a WebP with a .jpg name added by hand. Renaming a file does not change what is inside it, and the portal checks the real content. Converting the picture properly solves it in under a minute. If a form keeps refusing a file that looks correct, the content, not the name, is the thing to fix.
Opening WebP files on your own computer
If you only want to look at a WebP picture, not upload it, you rarely need to convert anything. Dragging the file into a modern browser window opens it straight away. Recent versions of Windows, macOS, Android and iOS also show WebP in their built-in galleries. The conversion becomes necessary only when another program or website refuses the file, and in that case it is the quickest and cleanest route.
Fixing it for good on your own website
If you run a website and your visitors complain that they cannot save or reuse your images, remember that your pictures are served in WebP for speed. That is usually a sound decision for the page itself. If you also offer downloads, such as printable posters or product photos for resellers, provide a JPG or PNG version for those. A small effort on your side saves frustration on theirs.
What about animated WebP?
WebP can hold animations, like a GIF. When you convert an animated WebP to JPG or PNG, you get a single still picture, not the whole animation. If you need the animation itself, you would need a tool designed for animated formats.
Quality and size after converting
JPG is a lossy format, so converting adds one more step of compression, which is why a high quality setting is a good idea. The JPG will often be larger than the WebP, since WebP is more efficient. That is normal. If the new file is too big for the form, resize it afterwards with the Image Resizer.
A quick checklist when an upload fails
- Check the file extension for .webp.
- Check the size limit of the form.
- Check the pixel size requirements, if any are given.
- Convert to JPG or PNG, then try again.
Once you know that WebP is the usual cause, the error stops being a mystery and becomes a thirty-second job.