What Is WebP
WebP is an image format introduced by Google that simultaneously supports lossy compression, lossless compression, and an alpha channel. In short, it aims to be a single format that replaces both JPEG and PNG—smaller size, more features.
All mainstream browsers (Chrome, Edge, Firefox, Safari) now support WebP, and websites using it to replace JPEG/PNG can significantly boost loading speed.
Main Advantages of WebP
Smaller Size
- Lossy WebP vs JPEG: 25%–35% smaller at equivalent visual quality
- Lossless WebP vs PNG: 20%–30% smaller
- Supports transparency: much smaller than transparent PNG—filling the gap left by JPEG's lack of transparency
For image-heavy websites, switching the whole site to WebP saves a lot of bandwidth and load time.
Comprehensive Features
- Supports an alpha channel (like PNG)
- Supports both lossy and lossless (like JPEG and PNG combined)
- Supports animation (like GIF)
- One format covers multiple use cases
Full Support in Modern Browsers
After 2020, all mainstream browsers support WebP display. The compatibility issues of earlier years are essentially gone.
Limitations of WebP
Old Environments Don't Support It
Old browser versions (IE, older iOS) don't support it. If your audience includes these, provide JPEG/PNG fallback.
Uneven Editing Software Support
Some older image-editing software can't directly edit WebP. But viewing and conversion tools have broad support.
Lossy WebP at Very Low Quality Can Lose to JPEG
When quality is compressed very low, WebP sometimes loses to JPEG. But in the normal-use quality range (70+), WebP is better.
WebP vs JPEG vs PNG
| Dimension | JPEG | PNG | WebP |
|---|---|---|---|
| Lossy compression | Supported | Not supported | Supported |
| Transparency | Not supported | Supported | Supported |
| Animation | Not supported | Not supported | Supported |
| Size | Medium | Large | Smallest |
| Compatibility | All platforms | All platforms | Modern browsers |
Conclusion: websites targeting modern browsers should prioritize WebP; for full-platform compatibility use JPEG/PNG; when you need transparency and a small size, WebP is the best choice.
Cases Suited to WebP
- Website images: replace JPEG/PNG to boost loading speed
- Transparent images: replace transparent PNG—size shrinks dramatically
- Animated images: replace GIF—smaller size, better quality
- In-app images: reduce package size
- CDN image assets: save bandwidth
Cases Not Suited
- External documents that need full-platform compatibility (PDF embedding, old environments)
- Audiences that include old browsers
- Images that need to be edited in old software
How to Convert
Use the Image Format Convert tool:
- Upload JPEG/PNG
- Choose WebP as the target format
- Set quality (lossy 80 approximates lossless)
- Convert and download
For batch conversion, set a unified quality—80 for photos, 90 for screenshots.
Compatibility with the picture Tag
To use WebP on a website while remaining compatible with old browsers, use the picture tag:
The source tag prioritizes WebP, and when unsupported falls back to the img's JPEG. This covers both sides.
Common Pitfalls
Size Gets Larger After Conversion
Lossless WebP is sometimes larger than a small JPEG. Use lossy WebP for photos—not lossless.
Quality 100 Doesn't Mean Lossless
WebP quality 100 is still lossy. For true lossless, choose the "lossless WebP" option, but the size will grow.
Transparent PNG Keeps Transparency When Converted to WebP
WebP supports transparency—PNG converted to WebP keeps transparent areas, unlike converting to JPG which needs a fill color.
Summary
WebP is the top choice for images on modern websites—smallest size, most complete features, and compatibility is no longer an issue. Photos, transparent images, and animations all work. Use the DocsAll format-conversion tool to batch convert to WebP—processing happens in the browser, and photos aren't uploaded. When you need to support old environments, use the picture tag for fallback.