TidyToolsWhere the .webp came from
You almost certainly didn't choose it. WebP is Google's image format, and websites serve it because it's roughly 25–30% smaller than the equivalent JPG, which makes pages load faster and costs the site less to run. When you save a picture from a page, you get whatever the page was serving — so the file lands on your computer as .webp whether or not anything on your computer can read it.
Browsers all display it happily, which is why it looks fine until the moment you try to do something with it. Then it stops: older versions of Photoshop refuse it, plenty of upload forms check the extension and reject it, print shops won't take it, and Windows Photo Viewer on an older machine shows nothing at all. Converting to JPG makes the problem disappear, because everything made in the last thirty years opens a JPG.
A worked example
You're putting together a slide deck and saved six product photos from a supplier's website. All six arrive as .webp, and PowerPoint on the company laptop won't insert them.
Drop all six in at once. They convert in place, keeping their full resolution, and you can take them individually or as a single ZIP. Nothing was uploaded to anyone, which matters more than it sounds when the images are an unreleased product.
The honest note about quality
WebP and JPG are both lossy formats, so converting between them means decoding one and re-encoding the other. That's a generation of loss — small, but real, and not something any converter can avoid. At the Maximum setting it is very hard to see even side by side; the file typically ends up somewhat larger than the WebP it came from, which is the trade you're making for compatibility.
If the file size matters more than the format, the honest answer is not to convert at all. If it has to be a JPG and it also has to be under a limit, convert here and then run it through the image compressor, which finds the best quality that fits your target rather than guessing.
Transparency, and why your background turned white
WebP can store transparency; JPG cannot, at all. There is no quality setting or clever trick that changes this — the format has no channel to put it in. When a transparent image becomes a JPG, every see-through pixel has to become something, and that something is white here.
If you need the transparent background — a logo to place over a coloured slide, say — choose PNG instead. It keeps transparency perfectly and is just as widely supported. The list flags any image that has transparency before you convert, so you find out now rather than after you've dropped a logo onto a dark background.
Animated WebP
Some WebP files are animations, the format's equivalent of a GIF. Neither JPG nor PNG can hold an animation, so what you get is the first frame as a still image. The tool says so on the row rather than quietly handing you a picture where you expected movement. If you need the animation itself, this is the wrong conversion.
Frequently asked questions
Are my images uploaded anywhere?
No. The conversion uses the same image engine your browser uses to draw pages, running on your own machine. There is no server, no account and nothing stored. Load the page once, go offline, and it still works.
Is there a limit, or a watermark?
Neither. Convert as many as you like — they're processed one at a time so the page stays responsive — and nothing is added to the output.
Will the image lose quality?
A little, unavoidably, because both formats are lossy and the picture has to be decoded and re-encoded. At the Maximum setting the difference is very hard to see. Nothing about this is specific to this tool — it's true of every WebP to JPG conversion anywhere.
Why did my transparent background go white?
Because JPG has no way to store transparency. Convert to PNG instead if you need it kept. Any image with transparency is flagged in the list before you convert.
Does it keep the original resolution?
Yes. The pixel dimensions are unchanged — nothing is resized or cropped. If you want it smaller, use the image compressor afterwards.
Can it convert AVIF as well?
Yes, along with PNG, GIF and BMP, provided your browser can decode them. AVIF is the newer format causing the same problem for the same reasons; Chrome, Edge, Firefox and Safari all read it now.
What about HEIC photos from an iPhone?
Those need a different decoder that desktop browsers don't include, so they have their own tool — the HEIC to JPG converter.
What happens to an animated WebP?
You get its first frame as a still image, because neither JPG nor PNG can store animation. The row tells you when this has happened.