WebP to JPG, in your browser
Drop a WebP file. Get a JPG. Conversion runs in your tab. Open DevTools and watch the Network tab to confirm nothing leaves.
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Files stay on your device. Nothing uploads.
Why convert WebP to JPG?
WebP is the smaller, smarter format that now ships natively in every modern browser. Pages load faster, image CDNs serve fewer bytes. But "modern browser" is not the whole world. A surprising amount of software still treats WebP as an unknown format and refuses to open it: older Microsoft Office releases, several email clients, many photo viewers on Linux distros without imagemagick installed, and roughly half of every "upload your photo" form on a corporate intranet.
When that compatibility wall hits, JPG is the universal escape hatch. It opens everywhere a raster image can possibly open. The trade-off is file size, sometimes 30-50 percent larger for the same visual quality, but a JPG that displays beats a WebP that does not.
How this converter works
Modern browsers ship a native WebP decoder. We hand your file to the browser via the createImageBitmap API, which produces an ImageBitmap object containing the decoded pixels. We draw that bitmap onto an OffscreenCanvas inside a Web Worker, then call convertToBlob with type "image/jpeg" and your chosen quality. The result is a JPG-encoded Blob that we hand back to the page so you can save it.
No WebAssembly module is involved. The decoder and the encoder are both built into your browser. This converter's manifest at /manifests/webp-to-jpg.json reflects that with an empty wasmModules array. The privacy guarantee is unchanged: no file ever leaves your device. Open DevTools, switch to the Network tab, drop a WebP, and watch. The only traffic is for our static assets.
Quality and file size
You can pick a JPG quality from 1 to 100; the default is 90. At 90 the visual difference between source and output is generally invisible to the human eye for photographic content. At 75 you see mild compression artifacts in skies and gradients. Below 60 the image starts to look obviously lossy.
For a typical 1920x1080 photographic WebP that runs around 200 KB, the JPG at quality 90 lands near 350-450 KB. At quality 75 it drops to roughly 200-280 KB. For UI screenshots with flat color regions, JPG performs poorly compared to WebP regardless of quality; consider converting to PNG instead if your image has hard edges and large solid areas.
What about transparency?
JPG has no alpha channel. Transparent pixels in your source WebP get flattened against a white background before encoding. If you have a logo on a transparent background and you care about that transparency, convert to PNG instead. The "WebP to PNG" converter is one click away.
If your WebP is mostly opaque with only a few transparent edges, the white-flattening usually goes unnoticed. If you need a different background color, consider opening the file in your image editor instead; we keep the conversion simple to keep the code small and auditable.
Speed and limits
Conversion happens in a Web Worker so the page stays responsive. A 4K WebP photo converts to JPG in well under a second on a modern laptop; older devices may take a couple of seconds for very large images. Memory usage scales with image area; 100-megapixel photos may exhaust your browser's memory budget. The "memory" line in the manifest gives a rough estimate.
You can drop multiple WebP files at once and they will queue. A future release will run them in parallel where memory allows.
Frequently asked questions
- Why is the JPG bigger than the WebP?
- JPG uses older compression. For photos, the JPG can be 20-40 percent larger than the WebP. For graphics with flat colors, the size difference is even larger. WebP simply compresses better.
- Does this work offline?
- After the first visit, yes. The Service Worker caches the page and the JavaScript. Disconnect from the internet, reload, drop a WebP, get a JPG.
- Will my transparency survive?
- No. JPG has no alpha channel. Transparent pixels get flattened to white. Convert to PNG if you need to preserve alpha.
- Can I batch convert?
- Drop multiple WebP files at once and they will process one after another. Aggregate progress is shown at the top of the queue; you can also download a single ZIP of every output.
- Where does the WebP decoder come from?
- The browser. We do not bundle a third-party WebP decoder for this converter. createImageBitmap is part of every major browser as of 2024.