Are my files uploaded to a server?

No. This conversion runs inside your browser using your own device’s processing power, and the file is not uploaded. Once a tool has been used once (video, text recognition and background removal download their engine from this site the first time), it keeps working when your connection drops.

Does every browser show WebP?

Current versions of Chrome, Edge, Firefox and Safari do. Older software might not, which is the case to keep a JPG copy for.

Is quality lost converting JPG to WebP?

Re-encoding costs a little, as with any lossy format. The quality score under the result shows how much, next to the new file size.

Convert JPG to WebP

Runs on your device · Your file never leaves your device.

WebP usually stores a photo in a smaller file than JPG at a similar look, which is why it is worth using for anything going onto a web page. Convert a whole folder at once and download them together.

For a photo-heavy site the saving adds up across a page full of images, so the page loads faster. Each result shows its new size next to the original, so the saving is measured for every file rather than promised.

Everything runs on your device with nothing uploaded, and you can set a hard size cap if a specific limit matters.

How to convert JPG to WebP

Add the JPGs you want to shrink.
Optionally set a size cap.
Press Convert — each result shows its new size and a quality score.
Download them together as a ZIP.

Supported formats and limits

Input: JPG photos
Output: WebP
Saving: Shown for every file: new size next to the original
Support: Every current browser
Where it runs: In your browser; nothing uploaded

Not for: Sending to someone on very old software — keep a JPG copy for anything that predates WebP support.

What happens to the JPG

The JPG is decoded by the browser and encoded again by libwebp in its lossy mode, at the quality on the slider, which starts at 85 and moves in steps of 5. This is a second lossy step on a picture that has already been through one, so the encoder also spends some bytes on the small square blocks the JPG left behind.

A JPG always becomes a lossy WebP here. The lossless mode is used only for PNG pictures (/png-to-webp), because it would carry every JPG block exactly and usually make the file larger rather than smaller.

How much smaller the WebP is depends on the JPG you start from. The result card shows the new size next to the original, so check it before replacing the files on a site. If a file did not get smaller, keep the JPG. In a batch, each file’s quality score and pixel size are listed under the download, so a picture that fared worse than the others is easy to find.

Scale photos to the size the page shows them

A photo straight from a phone or camera is usually far wider than any web page shows it. Type the width the page actually needs into Max width / height, and every image in the batch is scaled down, keeping its proportions, before it is encoded. The saving from fewer pixels and the saving from the format then add up. Pictures already smaller than that number are left at their size; the tool never enlarges.

WebP cannot store a picture wider or taller than 16,383 pixels, so a longer panorama or stitched scan is scaled down to that size, and its result says so.

Frequently asked questions

Are my files uploaded to a server?: No. This conversion runs inside your browser using your own device’s processing power, and the file is not uploaded. Once a tool has been used once (video, text recognition and background removal download their engine from this site the first time), it keeps working when your connection drops.
Does every browser show WebP?: Current versions of Chrome, Edge, Firefox and Safari do. Older software might not, which is the case to keep a JPG copy for.
Is quality lost converting JPG to WebP?: Re-encoding costs a little, as with any lossy format. The quality score under the result shows how much, next to the new file size.