WebP

Compress WebP

Up to 100 files at once. Mixed formats are fine.

Compressing a WebP re-encodes it at a lower quality, in your browser, with nothing uploaded. WebP already compresses better than JPEG, so the savings are smaller than you may be used to — and the same rule applies as everywhere else here: if the result is not smaller than what you dropped in, you get the original back.

Why there is less left to save

WebP is a more capable codec than JPEG. It predicts each block from its neighbours before compressing the difference, which JPEG cannot do at all, and the result is typically 25 to 35 per cent smaller at the same visual quality. Somebody arriving here has usually already taken that win.

What remains is the ordinary trade: lower the quality, lose some detail, save some bytes. Expect the numbers to feel less dramatic than compressing a JPEG, because the easy savings were collected when the file became a WebP.

The quality scale is not JPEG’s

Both formats offer a number from 1 to 100 and the numbers do not mean the same thing. WebP at 70 holds up about as well as JPEG at 80, so the reflex of "never go below 80" carries over as needlessly cautious and leaves savings on the table.

The reliable method is to look rather than to calculate. Compress, look at the result at the size it will actually be displayed, and adjust. The control sits under the result so that a second attempt costs one click.

Dimensions still matter most

For a website, the largest single saving is almost never the codec — it is not shipping a 3000-pixel image to a phone that will draw it 400 pixels wide. The resize control handles the simple version of that, and the proper version is a `srcset` with two or three widths, which the browser then picks from.

If you are optimising a page rather than one file, resizing first and compressing second is the right order. Compressing an oversized image produces a small file of a picture nobody needed at that size.

How to compress a WebP

  1. Drop your WebP onto this page, or click to choose one.
  2. It is re-encoded at the quality shown, in your browser.
  3. Compare the saving against how it looks, and adjust if there is more to take.

Compressing WebP: common questions

Does compressing WebP lose quality?
Yes — this re-encodes the image, and WebP’s lossy mode discards detail like JPEG does. WebP is better at hiding it, so a given number goes further, but the file is not identical afterwards. WebP also has a lossless mode; a file saved in it will not shrink much here, because there was no rounding to tighten.
Is the file uploaded?
No. The WebP is decoded and re-encoded in your browser through libwebp compiled to WebAssembly, so nothing is sent anywhere.
Should I use AVIF instead?
For a website, often yes — AVIF is typically 20 to 30 per cent smaller than WebP at matching quality. It encodes more slowly and support is newer, so the usual approach is to offer AVIF with WebP as the fallback rather than replacing one with the other outright.
Why did the file barely change?
Either it was already compressed hard, or it is a lossless WebP. In the second case there is no quality dial to turn — the file stores every pixel exactly, and re-encoding it as lossy is a different operation with a different result.

Sometimes the better answer is a different format — especially for a photograph stored as WebP.