Smaller Images, Same Picture
WebP was built to replace both JPEG and PNG on the web, and it generally does: lossy WebP runs around 25 to 35 per cent smaller than JPEG at comparable quality, and lossless WebP beats PNG by a similar margin while keeping transparency. On a page carrying a dozen photographs that difference is the gap between fast and sluggish.
This converter turns JPEG, PNG and other formats into WebP in your browser, with the quality setting under your control.
How to Convert Images to WebP
Quality is the only setting that matters, and the right value depends on what the image contains.
- Add the pictures you want to convert using the box above. Several at once is fine.
- Set the quality. Around 80 is the usual sweet spot for photographs, visually indistinguishable from the original at normal viewing size, at a fraction of the file size.
- Use a higher setting, 90 or above, for images with text, sharp edges or flat colour, where compression artefacts show more readily.
- Compare the resulting size against the original. If the saving is negligible, the source was probably already well compressed.
- Download the converted files. Your originals are untouched.
- Check the result at full size before replacing an original, particularly for anything containing small text.
Lossy, Lossless and Transparency
WebP has two distinct modes, which is unusual, JPEG is only lossy and PNG only lossless. Lossy WebP discards detail the eye is unlikely to notice, the same principle as JPEG but with better modern techniques. Lossless WebP preserves every pixel exactly, competing with PNG rather than with JPEG.
Transparency is where WebP genuinely has no competitor among the older formats. It supports an alpha channel in both modes, so a photograph with a transparent background can be lossy-compressed while keeping the transparency, something JPEG cannot do at all and PNG can only do at a much larger file size.
Format Comparison
What each format does well, and where WebP fits between them.
| Format | Compression | Transparency | Animation | Best for |
|---|---|---|---|---|
| JPEG | Lossy only | No | No | Photographs, universal support |
| PNG | Lossless only | Yes | No | Screenshots, logos, flat colour |
| GIF | Lossless, 256 colours | Yes (1-bit) | Yes | Legacy animation |
| WebP | Both | Yes | Yes | Most web images |
| AVIF | Both | Yes | Yes | Smaller still, slower to encode |
AVIF compresses better than WebP again, often by another 20 per cent, but encodes considerably more slowly and has slightly narrower support. WebP is the safer general default; AVIF is worth it for large images served at scale.
Support and When Not to Convert
Every current browser supports WebP, and has done since around 2020 when Safari added it. The remaining friction is outside the browser: some desktop applications, older email clients and a few content management systems still do not accept it. For an image someone will download and open in another program, JPEG or PNG remains the safer choice.
Converting an existing JPEG to WebP re-encodes it, which means a second round of lossy compression on top of the first. The saving is usually still worth it, but you cannot recover detail the JPEG already discarded, so convert from the highest-quality original you have rather than from a copy that has been through several rounds.