Same photo, a meaningfully smaller file
JPG has been the default photo format for decades, and it remains a solid choice - but it is not the most efficient one anymore. WebP was built afterward with the benefit of newer compression research, and it consistently produces smaller files than JPG at a quality level that looks the same to the eye. For a typical photo, 25-35% smaller is a reasonable expectation; busier, more detailed images sometimes save more.
What that saving costs you
Both JPG and WebP are lossy formats, so converting between them recompresses an image that has already been compressed once. At the high quality setting used here, that additional pass is not visible in ordinary viewing - it becomes a real concern only if you repeatedly convert the same file back and forth between lossy formats, where the losses compound each time. Keep an original JPG if you expect to need a pristine source again later.
Where the smaller file actually matters
| Use | Does the saving matter? |
|---|---|
| Website or web app images | Yes — directly affects page load speed |
| Large photo archive or backup | Yes — adds up across many files |
| Email attachment, browser-based client | Yes — faster to send and load |
| Printing, or software outside a browser | Check compatibility first — see below |
Where WebP still isn't accepted
Every current browser displays WebP with no issue - Chrome, Firefox, Safari, Edge have all supported it for years now. The gap sits outside browsers: some printer upload portals, older desktop photo editors, and phone apps with narrower format support can still reject a WebP file the moment it leaves a web page. If the image is headed somewhere outside a browser context, it's worth checking that WebP is accepted there before converting, or simply keeping the JPG for that particular use.
There is no transparency consideration here in either direction - JPG never had an alpha channel to begin with, so nothing is lost or needs to be filled in during the conversion.
A whole folder at once
Drop in as many JPG files as you have and each converts independently, with a single ZIP download once they are all done. There is no file count limit, since nothing is uploaded to a server that would need to handle the load.
Nothing is uploaded
Both the decoding and the encoding happen entirely inside your browser using canvas. Your photos never leave your device.