Bulk In-Browser WebP Image Converter
Convert many JPG or PNG images to WebP at once, with adjustable quality, processed in parallel by Web Workers in your browser.
Drop JPG or PNG files here, or click to browse
They stay on your device — nothing is uploaded.
Only applies in lossy mode — higher keeps more detail at a larger file size.
Forty images, one PageSpeed warning
Nadia writes a travel blog, and PageSpeed Insights keeps flagging the same thing: "Serve images in next-gen formats." She has forty photos across her recent posts, and converting them one at a time sounds like a lost weekend.
WebP files typically come out around 30% smaller than JPEGs at similar visual quality, which adds up fast on an image-heavy post. Drop the whole folder in here and get them back in one go. The photos get re-encoded on your own CPU, so a few hundred megabytes of full-size originals never have to crawl up a slow connection first.
How to convert JPG and PNG to WebP
- Drop your JPG or PNG files into the box above, or click it to browse. You can add as many as you like.
- Pick "Lossy (smaller files)" and set the Quality percentage (it starts at 80), or choose lossless if you need exact pixels.
- Press the Convert button and download the result: one WebP file, or a zip when you converted several.
Why a big batch doesn't freeze the page
The images are handed out to a small team of background workers, up to four depending on how many cores your device has. Each worker decodes a photo, redraws it, and saves it as WebP, then grabs the next in the queue. Your tab stays responsive while that goes on.
Your photos don't go anywhere
The conversion uses image-drawing features your browser already has. Files go from your disk to memory to the download, and no copy is stored on our side. That also means no daily image quota.
Watch out for older software and print workflows
WebP is great on the web, but some print shops, older editing programs and email clients still choke on it. Keep your original JPGs and PNGs, and treat the WebP files as the web copies.
Browser support for the encoding step also varies. Chrome, Edge and Firefox can write WebP from a canvas, while Safari may not, so if your output comes back as something other than .webp, try another browser. Metadata such as EXIF camera details isn't carried across either.
- No upload
- Every image is decoded and re-encoded locally in your browser — nothing is sent to a server.
- Quality only applies to lossy mode
- Lossless mode always preserves every pixel exactly, regardless of the quality percentage set.
Questions
What quality setting should I use to convert JPG to WebP?
The Quality field starts at 80%, which is a sensible default for photos. You usually can't see the difference from the original at that level, but the file is noticeably smaller. Drop toward 60 to 70 if you're chasing a PageSpeed score, and watch text and sharp edges, which show artifacts first.
What's the difference between lossy and lossless mode?
Lossy throws away fine detail your eye rarely notices, in return for much smaller files. Lossless keeps every pixel but gives larger files, so it suits screenshots, logos and flat graphics. The Quality percentage is ignored in lossless mode, and how strictly lossless is honoured depends on your browser's encoder.
Is PNG transparency preserved?
Yes. WebP supports an alpha channel, and the image is redrawn with its transparent areas intact. Converting a transparent PNG logo should leave a transparent WebP, though lossy mode can soften semi-transparent edges slightly.
Is there a limit on how many images I can convert at once?
There's no cap from us. The practical limit is your device's memory, since every file is held in the browser while it's processed. A few dozen photos are fine on most laptops, but for several hundred large originals, do them in batches.
How much smaller will my files be?
WebP photos commonly come out around 30% smaller than a JPEG at comparable quality, though results vary by image. PNG screenshots with flat colours often shrink by more, and a photo that's already heavily compressed JPEG may shrink less.
Are my images uploaded anywhere?
No. Each image is decoded and re-encoded inside your browser, and the finished files go straight to your downloads. The converted file also gets the same name as the original with a .webp ending, so you can swap them into your site easily.