Why convert PNG to WebP?
PNG files are losslessly compressed but large. A typical PNG product image with a transparent background can be 500 KB to 2 MB. The equivalent lossless WebP is 20-50 % smaller at the same pixel quality, and lossy WebP with transparency is often 60-80 % smaller than PNG at visually indistinguishable quality.
The key advantage of WebP over JPEG for PNG sources is transparency support. JPG cannot store alpha channels, so PNG with transparency must stay as PNG for the web — or switch to WebP, which supports transparent backgrounds and achieves smaller file sizes than PNG for the same content.
For e-commerce sites with thousands of product images on white or transparent backgrounds, the performance impact of PNG → WebP migration is dramatic: page LCP times drop, Google PageSpeed scores rise, and CDN costs fall. All modern major browsers support WebP with transparent alpha channels natively.
File Converter Pro encodes PNG → WebP offline on Windows 10 and 11. Transparency is preserved automatically. There is no upload step, no per-file limit, and no watermark.
How to convert PNG to WebP on Windows
- Install File Converter Pro. Download from the Microsoft Store. The free trial includes PNG to WebP conversion with full transparency support.
- Add PNG files to the queue. Drag PNG images or an entire folder into the app. PNG files with and without transparency (alpha channels) are both handled correctly.
- Choose lossy or lossless WebP. Lossy WebP at quality 80-85 gives the best size savings for photos and product images. Lossless WebP (near-PNG quality, smaller than PNG) is best for UI elements and line art.
- Convert offline. Click Convert. Output WebPs are saved to your folder. Transparency is carried over to the WebP alpha channel automatically.
Batch conversion for big folders
E-commerce catalogues, icon libraries, and UI design systems often have thousands of PNGs that all need WebP versions for modern web delivery. File Converter Pro handles these without any limits.
- Convert entire product image libraries in one batch job.
- Transparency preserved in every file — perfect for product cutouts and logos.
- Mirror folder structure on output for a drop-in replacement in your web project.
- Run offline without internet access — safe for proprietary product assets.
Quality settings that actually matter
- Lossless WebP: identical pixel quality to PNG, 20-30 % smaller. Ideal for UI elements, icons, and images where pixel-perfect quality matters.
- Lossy WebP quality 85: excellent visual quality, 50-70 % smaller than PNG for photographic content. The standard recommendation for product photos.
- Lossy WebP quality 75: web thumbnails and previews. Very compact, minor artefacts on close inspection.
- Alpha channel: preserved in both lossy and lossless WebP modes.
Common issues and fixes
- Transparency lost in output. Ensure you selected lossy or lossless WebP mode — both support alpha. JPG output would lose transparency; WebP should not.
- CMS does not accept .webp. Add .webp to your CMS allowed file types list. WordPress supports WebP natively since 5.8.
- Very small size savings for simple graphics. PNG-8 (palette-indexed) graphics are already small. WebP gains are most dramatic on PNG-24 photographic content and large illustrations.
- Old browsers show broken image. Use the picture HTML element to serve WebP to modern browsers and PNG as a fallback for IE11 and old Safari.
Related conversions
FAQ
Does WebP support transparency like PNG does?
Yes. Both lossy and lossless WebP support alpha channels (transparency). Your PNG transparent backgrounds and product cutouts carry over perfectly.
How much smaller will WebP be compared to PNG?
Lossless WebP is typically 20-30% smaller than PNG. Lossy WebP at quality 80-85 is often 50-80% smaller than PNG for photographic content. Results vary by image type.
Should I keep PNG files as fallback for older browsers?
For very old browsers (IE11, Safari pre-14) yes — use the HTML picture element with a PNG fallback. Most users (96%+) have WebP-capable browsers as of 2025.
Can I batch-convert an entire folder of PNG product images to WebP?
Yes. Drop the folder into File Converter Pro and every PNG is converted and saved to your output folder. Filenames are preserved with .webp extension.
Ready to convert your PNG files?
Download File Converter Pro from the Microsoft Store and convert your PNG images to WebP offline — transparency preserved, 50-80% smaller files, no upload, no watermark.