What is webp, and why does it only seem to happen on my computer?

webp is an image format used to cut down the size of images on web pages. When a site serves its images as webp, your browser stores exactly what it received, so the file lands with a .webp extension when you save it. It is not something going wrong on your machine — that page was serving webp all along. It also explains why some images save as jpg and others as webp: it depends on what each site chooses to serve.

Can I just rename the file to .jpg?

Renaming does not change the format. The extension is only part of the file name, and the data inside the file is still webp. Now the name and the actual contents disagree, so programs and upload forms that inspect the format may handle the file even less gracefully than before. To really change the format, the image has to be read and saved again through a conversion step.

Should I convert to JPG or to PNG?

It comes down to whether the image has a transparent background. JPG cannot carry transparency, so converting an image with a transparent background to JPG fills those areas with white. For logos, icons, or anything that needs an empty background, convert to PNG instead. For photos with a full background, JPG gives you a smaller file.

Can I convert several images at once?

Yes. Drop several files into an image conversion tool at once and pick the format you want. When you upload more than one, the results come back bundled as a single ZIP file, so there is no need to upload and download them one at a time.

Does converting hurt image quality?

JPG uses lossy compression, so some quality can be lost when the file is saved. As long as you keep the original, you can always convert again, so it is safer to hold on to the original file. If you want to preserve the image without any loss, choose PNG — but keep in mind that photos with complex colour can grow considerably as PNG.

Saved as webp? When you need webp conversion

Hand-drawn illustration of a single file icon stuck in front of a narrow slot, unable to fit through

The moment people go looking for webp conversion is usually the same one. You save an image you like from the web, the file name ends in neither .jpg nor .png but .webp, and the picture that looked perfectly ordinary on screen gets blocked the moment you try to upload it somewhere.

So this article focuses less on what webp is and more on where this file gets turned away. Once you know the point where it fails, it becomes obvious whether you need to change anything at all.

In five minutes you will

know why saved images land as .webp in the first place;
be able to tell exactly where the file really gets blocked;
be able to decide for yourself between JPG and PNG.

A webp file is not a broken file. Change it only when the side receiving it does not support it.

What just happened? An extension I have never seen

All you did was right-click and save an image, yet the file arrived with a name like photo.webp. It displayed fine on screen, so you assumed it would save as a jpg — and now that unfamiliar suffix makes you wonder whether the download went wrong.

The download did not fail. The file is intact and the picture inside it is unchanged. The only difference is the format the picture is stored in. Which is also why webp conversion is not always necessary.

Hand-drawn illustration of a single image file icon sitting in a downloads folder. It looks just like the files beside it, but the tail end of its label is drawn in an unfamiliar shape, with a question mark floating above it — The file is not corrupted — only the format it is stored in is unfamiliar.

An extension is a tag attached to the end of a file name. It signals how the data inside should be read. An unfamiliar tag does not mean there is anything wrong with the file.

Why did the file end up in webp?

webp is an image format used to reduce the size of images on web pages. A page with lots of photos means more data to download and a slower load, so fitting the same picture into a smaller file makes the page faster. That is why plenty of sites now serve their images as webp.

Your browser stores that image exactly as it received it. It simply moves the file it had already downloaded to display on screen onto your disk, so if the page was serving webp, the saved result is a .webp too.

The same reason explains why some images save as jpg and others as webp. Nothing changed in your computer's settings — different sites simply serve different formats.

STEP 1

The site serves it

In a size-reduced format

STEP 2

The browser receives it

Displays normally on screen

STEP 3

Saved exactly as received

Hence .webp

Saving does not change the format — the format it arrived in simply stays

So what actually changes for me?

Viewing it on screen is rarely a problem. Major browsers display webp, and it often opens in the default photo app or in Paint on recent versions of Windows too. So saying "webp files don't open" is not accurate.

The real snag sits somewhere else. There are cases where upload forms, document insertion, or certain programs reject it or do not support it. Being able to open a file and being willing to accept it are two different things.

Situation	What usually happens
Opening it in a browser	Major browsers display it
Attaching it to a submission form	Some sites limit accepted formats to jpg and png
Inserting it into a document or slide deck	Depends on the program and its version
Sending it to a print shop or vendor	Check the format they ask for first

That makes the deciding factor for webp conversion not the format itself but the side receiving it. Looking fine on your screen is no guarantee it will be accepted, and if nothing has blocked it anywhere, there is no reason to change it.

Hand-drawn illustration of a file icon stopped in front of a narrow slot in a wall, its corner caught on the edge, while another file beside it has already passed through and sits inside — Nothing is wrong with the file — the slot on the receiving side is simply a fixed shape.

Can I just rename it to .jpg?

It is the first idea that comes to mind, but it does not work. Changing the extension to .jpg does not change the format. The data inside the file stays exactly as it was.

All you have done is swap the label, so the visible name and the actual contents no longer agree. Programs and upload forms that inspect the format may treat the file even less predictably as a result. To genuinely change the format, the picture has to go through a conversion that saves it again.

What does not work

Editing the letters at the end of the name

Renaming photo.webp to photo.jpg only swaps the tag. The data inside is untouched, so the format is unchanged.

What does work

Saving it again in a different format

Reading the picture and saving it fresh in the format you want is what real webp conversion means. Upload the file to Image Converter and choose JPEG or PNG; if you upload several at once, the results come back bundled as a single ZIP.

JPG or PNG for the webp file?

There is only one thing to watch out for here. JPG cannot carry transparency. So when you convert an image with a transparent background to JPG, the areas that were transparent get filled with white.

For a logo, an icon, or any picture whose background you deliberately removed, that stings. Place it over a coloured background and the white rectangle shows up plainly. Convert those to PNG instead and the transparent areas stay transparent.

Hand-drawn illustration comparing two identical star shapes side by side. The left one has an empty background so the colour underneath shows through; the right one is surrounded by a white rectangle that hides the colour below — Transparent areas get filled with white. Keep pictures that need an empty background as PNG.

If your image is	Use this format
A photo with a full background	JPG (smaller file)
A logo or icon with a transparent background	PNG (transparency preserved)
Headed somewhere that specifies a format	Exactly the format specified

Turning a photo with complex colour into a PNG can make the file considerably larger. JPG, on the other hand, uses lossy compression, so a little quality can be given up in the saving. That is why it is safer to keep the original file rather than delete it.

Ready to try webp conversion?

webp conversion takes nothing more than uploading the file to Image Converter and choosing JPEG or PNG. There is no install and no sign-up, and you can upload several images at once.

If the size or the dimensions bother you afterwards, you can keep going from there. When a file is too heavy for an attachment limit, trim it with Image Compressor; when the recipient specified pixel dimensions, match them with Image Resizer.

Blocked by an upload form: check the accepted-format notice first and convert to that format
The image has a transparent background: choose PNG, not JPG (transparency turns white)
Caught by a size limit: convert first, then compress
Nothing has blocked it anywhere: you can leave it as it is

With any service that processes uploaded files, how long those files stay on the server is always the thing to check. Retention periods and deletion policies differ from service to service.

So for personal images such as photos of people, it is worth making a habit of reading each service's own official notice before you use it.

References

Google Developers, official documentation on the WebP image format. developers.google.com/speed/webp
MDN Web Docs, guide to image file types used on the web. MDN Image file type guide

This article is provided for general information only. Whether a particular format is supported can vary with the operating system, the program, its version, and each service's own policy, so check the official guidance of the relevant organisation or service for the file formats and size limits it requires. The statements here reflect the position at the time of writing (August 2026). Changing the format of a copyrighted image does not change what you are permitted to do with it, so check the original creator's terms of use before downloading and reusing anything.

Frequently asked questions

: webp is an image format used to cut down the size of images on web pages. When a site serves its images as webp, your browser stores exactly what it received, so the file lands with a .webp extension when you save it. It is not something going wrong on your machine — that page was serving webp all along. It also explains why some images save as jpg and others as webp: it depends on what each site chooses to serve.
: Renaming does not change the format. The extension is only part of the file name, and the data inside the file is still webp. Now the name and the actual contents disagree, so programs and upload forms that inspect the format may handle the file even less gracefully than before. To really change the format, the image has to be read and saved again through a conversion step.
: It comes down to whether the image has a transparent background. JPG cannot carry transparency, so converting an image with a transparent background to JPG fills those areas with white. For logos, icons, or anything that needs an empty background, convert to PNG instead. For photos with a full background, JPG gives you a smaller file.
: Yes. Drop several files into an image conversion tool at once and pick the format you want. When you upload more than one, the results come back bundled as a single ZIP file, so there is no need to upload and download them one at a time.
: JPG uses lossy compression, so some quality can be lost when the file is saved. As long as you keep the original, you can always convert again, so it is safer to hold on to the original file. If you want to preserve the image without any loss, choose PNG — but keep in mind that photos with complex colour can grow considerably as PNG.

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