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JPG to WebP converter

Convert JPG files to WebP inside this page. No upload, no limit on how many, no watermark.

  • 0 uploads
  • No limits
  • No signup
  • Works offline

JPG and WebP, side by side

JPEGWebP
Released19922010
Compressionlossyboth
Transparencynoyes
Animationnoyes
Supporteverywhere, without exceptionall current browsers; patchy outside them

What actually changes

The most common optimisation for a website. Expect 25–35% smaller files at visually identical quality. Serve WebP with a JPEG fallback and older clients still work.

JPEG is the format the web was built on, using discrete cosine transform compression tuned for photographs, released in 1992. Its real strength is that universal compatibility — every device, browser, printer and form on earth reads it. The reason you are on this page is almost certainly the other side of that coin: no transparency, visible ringing around sharp edges and text, and a compression scheme three decades behind the state of the art.

WebP arrived in 2010 and is Google's replacement for both JPEG and PNG, derived from the VP8 video codec. It gives you roughly 25–35% smaller than JPEG at matching visual quality, with transparency and animation in the same container. The trade-off worth knowing about before you commit: still refused by some desktop applications, older phones and a surprising number of official upload forms.

How the conversion works here

Your file is decoded in a Web Worker inside this browser tab — by the browser's own image pipeline where it can, and by a WebAssembly build of libheif or libavif where it cannot. The decoded pixels are then re-encoded with Google's libwebp, the same encoder Squoosh uses.

All of that happens on the processor in front of you. There is no upload step, no queue and no server, which is why there is no size cap, no daily allowance and no paid tier — and why the whole thing keeps working with the network switched off.

Doing more than one thing

Most people converting a format also need it smaller or a different size. The result screen hands your converted files straight to the compressor or the resizer in one click — no second download, no re-selecting files. If you need several formats, the general converter lets you pick the output each time.

How it works

  1. 01Add your JPG filesDrop them on the page, click to browse, paste from the clipboard, or drop a whole folder.
  2. 02Conversion runs on your deviceEach file is decoded and re-encoded as WebP by a WebAssembly codec in a background thread. Nothing is uploaded.
  3. 03Adjust if you need toMove the quality slider — 90 is visually indistinguishable from the source for most photographs.
  4. 04DownloadSave one file, or take the whole batch as a zip built on your device.

Questions people actually ask

Why convert JPG to WebP?
JPEG is the format the web was built on, using discrete cosine transform compression tuned for photographs. Its weakness is that no transparency, visible ringing around sharp edges and text, and a compression scheme three decades behind the state of the art. WebP gives you roughly 25–35% smaller than JPEG at matching visual quality, with transparency and animation in the same container, which is usually the reason people make this exact conversion.
Will I lose quality?
A little, unavoidably. JPEG and WebP are both lossy, so this is a re-encode. At quality 90 the difference is invisible at normal viewing size; drop below about 75 and it starts to show in skin tones and gradients.
Is there a file size or batch limit?
No. Nothing is uploaded, so there is no bandwidth to pay for and nothing to ration. The only ceiling is your own device’s memory.
Are my files uploaded?
No. Open your browser’s developer tools, watch the Network tab, and convert something — no request carries your file. The counter in the page header measures the same thing continuously.
Where is WebP supported?
All current browsers; patchy outside them. WebP arrived in 2010, and still refused by some desktop applications, older phones and a surprising number of official upload forms.

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