What is WebP?

Image2 min read

What WebP does differently, how well it is actually supported in 2026, when it is the right default, and the cases where it still is not.

In short

WebP is a modern image format that compresses better than JPEG at the same visual quality and supports transparency like PNG. Every current browser displays it. The main reason not to use it is software outside the browser that cannot read it.

WebP is an image format from Google that does both jobs JPEG and PNG do separately: it has a lossy mode that beats JPEG on file size at matching quality, and a lossless mode with transparency support like PNG.

What it does differently

Lossy WebP borrows its techniques from video encoding — it came out of the VP8 codec. The most useful of those is prediction: rather than describing each block from scratch, it predicts a block from its already-decoded neighbours and stores only the difference. Photographs have a great deal of local similarity, so there is a lot to predict, and that is most of where the saving comes from.

It also supports an alpha channel in both modes, which JPEG has never had. That combination — photographic compression plus transparency — is the thing neither older format could do.

Support in practice

Every current browser renders WebP, and has for years: Chrome, Edge, Firefox, Safari and everything built on them. On the web it is simply not a compatibility question any more.

Outside the browser is where it still bites. Some desktop image viewers, older design software, certain upload forms and a good number of internal business systems will not accept a .webp file. If you are handing an image to a person rather than publishing it to a page, JPG remains the safer choice.

Choosing between the three
SituationBest choiceWhy
Photograph on a web pageWebPSmallest file at the same visual quality
Logo or graphic with transparencyWebPMuch smaller than PNG, alpha preserved
Emailing a photo to someoneJPGOpens in anything, anywhere
Uploading to a form that rejects itJPG or PNGCompatibility beats efficiency
Screenshot you will edit againPNGLossless, no accumulating damage

Using it in Dexta

Compress Image has a Convert to WebP option alongside the quality slider, and switches it on automatically for PNG sources — because PNG ignores the quality slider entirely, converting to WebP is the only way to make a PNG meaningfully smaller there. Convert Format will also move an image between JPG, PNG and WebP directly.

Mistakes worth avoiding

  • Converting your only copy to WebP before checking the destination accepts it.
  • Converting an already-compressed JPEG to WebP and expecting the original quality back. The damage came along; you have just re-packaged it.
  • Using lossy WebP for screenshots at a low quality. It is better than JPEG at edges, but not immune — keep the quality high or stay on PNG.