Quick answer
WebP is smaller (typically 25-30% smaller than PNG) and better for web. PNG is more compatible, universal, and better for images with text and transparency. For modern websites, use WebP with PNG fallback. For compatibility and print, use PNG.
Both formats support transparency, but WebP is newer and more efficient. PNG is older and nearly universal. Here is when to use each.
File size comparison
WebP typically wins on file size:
- PNG (lossless): average 200 KB for a typical product photo with transparency.
- WebP (lossless): average 150 KB for the same image (25-30% smaller).
- WebP (lossy at quality 85): average 80 KB (60% smaller than PNG).
The file size savings of WebP over PNG are significant enough to matter on sites with hundreds of images.
Transparency: both support it equally
Both PNG and WebP support full 24-bit transparency (alpha channel). For images with transparent backgrounds:
- PNG: always lossless with transparency, no artifacts.
- WebP: can be lossless (preserves all transparency) or lossy (may introduce slight color shifts near edges).
For critical design work, PNG lossless is slightly safer. For web use, WebP lossless is fine.
Browser and software support
Current support:
- PNG: 99.9% of everything (browsers, email, design software, printing).
- WebP: 96-97% of modern browsers, less support in Outlook, Office, design tools.
If you need to send images via email or open in older Photoshop, PNG is safer.
Use WebP when
- Building a modern website for desktop and modern mobile browsers.
- You can serve both formats (WebP to modern browsers, PNG fallback).
- File size and page load speed are critical.
- Images have transparency and you are comfortable with lossy WebP.
Use PNG when
- You need universal compatibility (email, old software, printing).
- Images have text or fine details where compression artifacts are unacceptable.
- You are distributing files to people with mixed software.
- You need guaranteed lossless transparency.
What about animated images?
Both formats support animation (APNG for PNG, animated WebP). WebP animation is more efficient (smaller file size), but APNG is better supported in browsers. For animations:
- WebP animated: 40-50% smaller than APNG, but older browsers may not play it.
- APNG: slightly larger, but wider browser support.
- GIF: older, larger files, but universally supported.
For modern sites, animated WebP with GIF fallback is the best approach.
At-a-glance comparison
| Factor | WebP | PNG | Winner |
|---|---|---|---|
| File size (transparency) | 25-30% smaller | Baseline | WebP |
| Lossless quality | Identical | Identical | Tie |
| Lossy quality | Good | N/A | WebP |
| Browser support | 96-97% | 99.9% | PNG |
| Email compatibility | Limited | Universal | PNG |
| Design software support | Limited | Universal | PNG |
| Transparency quality | Good (lossy may shift) | Perfect (lossless) | PNG |
| Animation | Efficient | Supported | Tie |
