Convert JPG to WebP
Convert JPG to WebP in the browser with an adjustable quality slider. Usually 25-35% smaller than the JPEG for the same visual quality.
- Runs in your browser
- Files are never uploaded
- Free, no account
Pixel-perfect output. Expect files several times larger than the quality slider produces.
Off keeps the alpha channel. Turn it on to paint a solid background behind transparent pixels.
Metadata is stripped. Re-encoding rebuilds the file from raw pixels, so EXIF — GPS coordinates, camera model, serial number, capture time — and any XMP or IPTC block are dropped. Pixels are written in sRGB.
Nothing leaves this tab. The encoders are WebAssembly builds of libjpeg-turbo (MozJPEG), libpng/oxipng, libwebp and libavif running inside a worker on your machine.
How to convert JPG to WebP
- Drop your JPG or JPEG files above — the whole folder at once if you are optimising a site.
- Set the quality slider. 80 is the standard starting point; the per-file before/after sizes tell you immediately whether you can go lower.
- Compare the numbers. Every file shows its original size, its WebP size and the percentage change, so you can spot the rare image that gets larger.
- Download the files individually, or all of them as one ZIP.
How much you actually save
The often-quoted figure is "25–34% smaller than JPEG", which comes from Google's own study comparing libwebp against libjpeg at matched SSIM. That number holds up reasonably well in practice, but the spread is wide and depends almost entirely on image content:
| Content | Typical saving at matched quality | Notes |
|---|---|---|
| Skies, gradients, studio backdrops | 35–50% | Smooth regions are where WebP is strongest |
| Portraits and product shots | 25–35% | The typical case; matches the headline figure |
| Landscape with dense foliage | 10–20% | High-frequency detail is expensive in any codec |
| Film grain or high-ISO noise | 0–10%, occasionally larger | Noise is incompressible; check the before/after figures |
| Already heavily compressed JPEG | varies | Re-encoding artefacts costs bits — raise quality to 85 |
About re-encoding a lossy file
Converting JPG to WebP means decoding one lossy image and encoding it with a second lossy codec. In principle that compounds the damage. In practice it is a non-issue if you keep quality at 80 or above, because the JPEG artefacts are low-contrast and WebP spends very few bits describing them.
Where it does matter is repeated round trips. If you have the original camera file or the export from your editor, convert that to WebP rather than converting an already-compressed web JPEG. One lossy generation always beats two.
Using WebP on a real website
- Serve WebP with a JPEG fallback through a picture element, or let your CDN negotiate on the Accept header. Every current browser accepts WebP, but the fallback costs nothing.
- Keep your JPEG originals. WebP is a delivery format, not an archive format.
- Resize before you compress. Shrinking a 4000 px photo to the 1200 px it is actually displayed at saves far more bytes than any codec choice.
- Set explicit width and height attributes so the layout does not shift while images load.
If you want to push file sizes down further, AVIF is typically another 20–30% below WebP — with much slower encoding. Going the other way, WebP to JPG restores compatibility with older software, and the universal image converter handles mixed batches.
Questions
How much smaller is WebP than JPEG?
At matched visual quality, WebP is normally 25–35% smaller than a MozJPEG-encoded JPEG. The saving is biggest on smooth images such as gradients and skies, and smallest on noisy or heavily textured photographs.
Am I losing quality twice?
Technically yes — the JPEG is decoded and then re-encoded, so artefacts from the first pass are re-compressed. Keep quality at 80 or above and the second generation is visually indistinguishable in practice.
What quality should I pick for a website?
Start at 80. Hero images and product photos usually look right at 82–85; thumbnails and background textures survive 65–75 easily. Compare the before/after sizes shown for each file and pick the lowest that still looks clean.
Should I use WebP or AVIF?
AVIF files are smaller again — often 20–30% below WebP — but encode far more slowly and are unsupported in a handful of older browsers. WebP is the safe default; use AVIF when the bandwidth saving matters more.
How much smaller will the WebP be?
For photographs, expect 25–35% off the JPEG at visually matched quality. The saving is largest on images with smooth gradients and smallest on already heavily compressed JPEGs, where there is little redundancy left to remove.