This conversion usually makes the file bigger, and that is fine
Almost every other converter on this site exists to make something smaller. This one does not, and it is worth saying so plainly at the top rather than letting you discover it in the download folder.
WebP is a newer format than JPEG and better at the same job. Google’s own figures put it roughly a quarter to a third below comparable JPEG on photographs, and on flat graphics the gap is far wider. Converting the other way therefore means a larger file for the same picture — sometimes several times larger.
Six real encodings, measured while this page was built. The same three pictures, saved as WebP at quality 85, then converted to JPEG:
So why do it at all? Compatibility. Something you need to send this picture to does not accept WebP: older versions of Office, a number of print workflows, some older phones, and a long tail of upload forms that check the file extension. JPEG is understood by everything that has ever opened an image. That is a perfectly good reason to convert, and the extra bytes are what it costs.
What would not be acceptable is not being told. Every row on this page shows both sizes, and growth is reported as growth.
Animation: the thing most WebP converters lose without mentioning
WebP can hold an animation, in much the same way a GIF does — many frames with timing between them. JPEG holds exactly one picture.
Convert an animated WebP to JPEG in a browser and you get its first frame. Every other frame is discarded, silently, because the conversion happens on a canvas and a canvas holds one frame at a time. If you have ever converted a WebP sticker or a short looping clip and wondered why it came back as a still, that is why.
This page reads the file’s container before converting anything and tells you. A WebP is a RIFF file: a short header, then a list of chunks. An extended-format file carries a flags byte saying whether it is animated, and each frame is its own ANMF chunk. Counting them is exact and costs nothing, so the warning can say how many frames you are about to lose rather than just that something will be lost.
If the movement matters, JPEG is the wrong destination entirely. Convert to GIF instead — the MP4 to GIF Converter and the GIF Maker both keep animation.
Transparency, and the difference between claiming it and using it
WebP carries transparency; JPEG has no alpha channel at all. Anything see-through must become a solid colour, and this page lets you choose which rather than defaulting to white and saying nothing.
There is a subtlety worth knowing. The same container header that declares animation also declares alpha — but a file can declare an alpha channel and use it for nothing, every pixel fully opaque. Warning on the flag alone would nag people about a problem they do not have. So this page checks the flag first, and only if it is set does it look at the actual pixels before deciding whether to say anything. Header first because it is free; pixels second because they are the truth.
Choosing a quality, and why very high is usually wasted here
The quality slider runs from 10 to 100. For photographs, 75 to 85 is the usual sweet spot, and below about 70 the artefacts start to show in smooth gradients.
Pushing past 90 is particularly wasteful on this page. If the WebP you started with was lossy, it has already discarded detail; asking JPEG to store what remains with extreme fidelity inflates the file sharply and recovers nothing. The measurements above show it clearly — the same photograph went from 11% smaller at quality 85 to 70% larger at quality 95, for no visible gain.
If a limit is what you are working to — an upload form that refuses anything over 200 KB — name the size instead. The tool then searches for the answer rather than making you guess: nine encodings narrowing in on the highest quality that still fits, and an honest report when the target cannot be reached at all.
Questions people ask about WebP to JPG
Why is my JPG bigger than the WebP?
Because WebP compresses better. It is not a fault in the conversion, and there is no setting that reverses it — only a lower quality, which costs picture quality rather than fixing anything. If size is what you care about, keep the WebP.
Will I lose quality converting WebP to JPG?
A little, yes. JPEG is lossy, so it discards something on the way in. If the WebP was itself lossy, you are now on a second generation of loss. At quality 80 or above on a photograph you are unlikely to see it.
My animated WebP became a still picture. Can that be fixed?
Not by converting to JPEG — the format has nowhere to put the other frames. Convert to GIF instead if you need the movement, or keep the WebP.
What happened to my transparent background?
It became the colour you chose above; white if you left it alone. JPEG has no transparency channel. To keep it, stay with WebP or use PNG.
Can I convert several files at once?
Yes, up to 30, with the same settings. Each row shows its own before-and-after size, and any file that was animated or had transparency says so on its own line.
Why does my browser show WebP fine but this other program will not open it?
Browser support has been universal for years, as caniuse records; support in desktop applications, print workflows and upload forms lags well behind. That gap is the whole reason this page exists.
Is there a better format to convert to?
If whatever you are sending it to accepts PNG, that is lossless and keeps transparency — larger again, but nothing is discarded. The Universal Image Converter will show you the actual size in each format for your own picture before you choose.
Are my images uploaded?
No. Everything happens inside this page on your own machine. Nothing is sent anywhere and nothing is stored.
Where the facts on this page come from
- WebP, Google, for the lossy and lossless modes and the comparison against JPEG.
- WebP Container Specification, Google — the RIFF layout, the VP8X flags byte and the
ANMFframe chunks this page reads to detect animation and alpha. - ITU-T T.81, the JPEG standard, which defines no transparency channel and no animation.
- caniuse — WebP, for browser support.
- MDN — HTMLCanvasElement.toBlob(), which does the encoding here and takes the quality argument the size search adjusts.