How this works in your browser
The PNG is decoded onto an HTML5 canvas and re-exported using the browser’s built-in WEBP encoder. WEBP gets its size advantage by borrowing prediction techniques from video compression, encoding each block in terms of its neighbours rather than storing every pixel independently the way PNG’s DEFLATE stream effectively does. Crucially for this direction, WEBP supports a full alpha channel, so transparency survives the conversion rather than being flattened. Everything runs locally in your browser tab, so no image is uploaded to be compressed.
PNG to WEBP vs. traditional online converters
| Feature | PNG to WEBP (in-browser) | Traditional online converters |
|---|---|---|
| File upload required | No - never leaves your device | Yes - file is sent to a server |
| Processing queue | None - starts instantly | Often, especially at peak times |
| Watermark on output | Never | Common on free plans |
| Usage limits | None - free, unlimited use | Often capped per day or file size |
| Works offline once loaded | Yes, for most tools | No - requires a live connection |
| Account required | No | Often, for anything beyond a trial |
Who uses PNG to WEBP
Cutting page weight
Replace heavy PNG assets with WEBP to reduce bytes on a page without a visible change in quality.
Shrinking transparent graphics
Compress logos, icons and cut-outs that need transparency and would otherwise have to stay as large PNGs.
Preparing modern web assets
Produce the WEBP variants expected by current build pipelines and CMS image handlers.
How to use PNG to WEBP
- 1
Open the PNG to WEBP converter
Go to tools.slaytic.com and open the PNG to WEBP tool. No sign-up or account required.
- 2
Drop your PNG file
Drop your PNG onto the tool, or click to browse and select it from your device. Nothing is uploaded.
- 3
Download your WEBP
The tool re-encodes the image as WEBP, keeping any transparency, and hands you the smaller file to download.
Frequently asked questions
Is transparency preserved?
Yes. WEBP supports an alpha channel just like PNG, so transparent areas convert correctly.
Will every browser support the WEBP output?
Yes. All modern browsers (Chrome, Firefox, Safari, Edge) support WEBP natively.
How much smaller will the file be?
It varies by image, but WEBP is typically 25-35% smaller than an equivalent-quality PNG.
Should I delete the original PNG?
Keep it as your master copy. WEBP is an excellent delivery format for the web, but PNG remains the safer archive: it is lossless, universally supported, and you can always re-export WEBP from it later.
Does WEBP help with Core Web Vitals?
It can. Images are usually the heaviest thing on a page, so cutting 25-35% off them directly reduces bytes downloaded, which is what Largest Contentful Paint is most often waiting on.
Is my image uploaded anywhere?
No. The re-encode runs entirely inside your browser tab.