Convert JPG to WebP

Images are usually the heaviest part of a web page, and the largest one is often what visitors wait for before the page feels ready. Search engines measure that wait as Largest Contentful Paint. Serving the same picture in fewer bytes shortens it, especially on phones and slow connections.

WebP typically reaches the look of a JPG in noticeably fewer bytes, and every browser in current use, from Chrome and Edge to Firefox and Safari on iPhone, can display it. Most site builders and content management systems accept .webp uploads as well, so for a website the switch is usually painless.

WebP is a web format. Outside the browser it is less welcome: some email programs, older office software, print services, photo kiosks and many official upload forms still want JPG. Keep your JPG originals, and use WebP for the copies you publish online.

Converting an already compressed JPG to WebP compresses it once more. At the default quality the result is very hard to tell apart, but it is not a way to recover detail, and repeated round trips between formats slowly wear a photo down. Convert from the best original you have.

Ask Safari’s canvas for a WebP file and it quietly returns a PNG instead. A converter that trusts the browser would hand you a PNG with a .webp name. Image Studio checks the real type of every file it writes. In Safari it switches to a WebP encoder compiled to WebAssembly, served from this site and kept by your browser after the first use.

The result is the same kind of WebP file whichever browser you use, and the page tells you before it loads the encoder.

The default quality is chosen for photos on the web. Lower it for thumbnails and backgrounds where a little softness doesn’t matter; raise it for portfolio images. If a file must stay under a size, set a limit in KB under More options and the quality is found for you.

WebP has a hard limit of 16,383 pixels on each side. Web photos are far smaller, but a stitched panorama can exceed it, so set a longest side first for very wide images. Photos are saved as lossy WebP, the right kind for camera pictures; JPGs have no transparency, so there is none to carry over.

Product shots before a launch, client photos, unreleased designs: the images people prepare for a website are not always public yet. This conversion runs inside your browser, so they never pass through anyone else’s server on the way.

Camera details and GPS coordinates in the JPG are left out of the WebP, which is what you want for anything going on a public site.

You don't have to take our word for it. Three checks:

1. Open your browser's developer tools, choose the Network tab, then open and save an image. No request carries your file.
2. Open an image here once, then turn on airplane mode and run the same job again. It still works, because nothing needs a server.
3. Read the page's response headers: its Content-Security-Policy lets it connect only to this site itself, so there is no outside host a file could go to.

How it works, and how to check it yourself