Format
What Is WebP? The Modern Web Image Format Explained
WebP is Google's open image format designed as a modern replacement for JPEG and PNG — smaller files, same visual quality, with full support for transparency and animation.
What is WebP?
WebP is an image format developed by Google and released in 2010. It was created specifically for the web, with the goal of reducing image file sizes without sacrificing visual quality. Unlike older formats that were adapted for web use, WebP was designed from the ground up for fast web delivery.
The format supports both lossy and lossless compression, an alpha channel for transparency, and animation — making it capable of replacing JPEG, PNG, and GIF in a single format. As of 2024, all major browsers fully support WebP, making it the default choice for web image delivery.
How WebP compression works
WebP's lossy compression is based on the VP8 video codec — it treats each image frame the way a video codec treats a key frame, using predictive coding and discrete cosine transforms (DCT) to encode image blocks efficiently. This is why WebP lossy consistently outperforms JPEG, which uses an older DCT implementation without predictive coding.
WebP's lossless compression uses VP8L encoding, which applies spatial prediction, color space transforms, LZ77 backward references, and Huffman coding. The result is a lossless file that is typically 25–35% smaller than an equivalent PNG.
Both modes support an 8-bit alpha channel. In lossy mode, the alpha plane is encoded separately with lossless VP8L, meaning transparency is always pixel-perfect even when the color data is lossy-compressed.
File size comparison
WebP's size advantage over older formats is consistent across image types. The gains are largest for photographic content and somewhat smaller for flat graphics.
| Format | Relative size (photo) | Relative size (graphic/logo) | Notes |
|---|---|---|---|
| JPEG | 100% | — | No alpha, no animation |
| PNG | 300–500% | 100% | Lossless only, large for photos |
| WebP (lossy) | ~65% | ~70% | Best for photos with alpha |
| WebP (lossless) | ~180% | ~75% | Best for UI/logos |
| AVIF | ~50% | ~60% | Slower encode, wider color |
In practice, converting a 1 MB JPEG photo to lossy WebP at quality 80 typically yields a 600–700 KB file with visually identical results. Converting a 500 KB logo PNG to lossless WebP often produces a 350–400 KB file with exactly the same pixels.
Browser and OS support
| Platform | Support | Since |
|---|---|---|
| Chrome | Full | Chrome 9 (2011) |
| Firefox | Full | Firefox 65 (2019) |
| Safari | Full | Safari 14 / iOS 14 (2020) |
| Edge | Full | Edge 18 (2018) |
| Windows | Full (Photos app, etc.) | Windows 10 1809+ |
| macOS | Full | macOS 11 (2020) |
| Android | Full | Android 4.0+ (2011) |
| iOS | Full | iOS 14 (2020) |
The only meaningful legacy gap was iOS Safari before iOS 14. Since iOS 14 launched in September 2020, the installed base of pre-WebP iOS devices is now negligible for most websites. For absolute maximum compatibility with legacy email clients and old Office workflows, JPEG or PNG is still the safest choice.
When to use WebP
WebP should be your default format for web image delivery. It handles every major use case better than the format it replaces:
- Photos on the web: Use lossy WebP instead of JPEG. Same visual quality, 25–35% smaller.
- Logos and UI graphics with transparency: Use lossless WebP instead of PNG. Same pixel-perfect output, typically 25–35% smaller.
- Animations: Use animated WebP or MP4 instead of GIF. Dramatically smaller, better color depth, proper alpha.
- Icons and favicons: SVG is still better for infinitely scalable vector icons; use WebP for raster icon sprites.
Stick with JPEG for print workflows, email attachments sent to unknown clients, or any system that explicitly requires JPEG. Stick with PNG for raw archival files you'll edit repeatedly.
WebP vs alternatives
| Format | Compression | Alpha | Animation | Browser support | Best use |
|---|---|---|---|---|---|
| WebP | Lossy + Lossless | Yes (8-bit) | Yes | All modern (2020+) | Web delivery default |
| JPEG | Lossy only | No | No | Universal | Print, legacy compat |
| PNG | Lossless only | Yes (8-bit) | No (APNG only) | Universal | Archival, editing masters |
| AVIF | Lossy + Lossless | Yes | Yes | Chrome/Firefox/Safari 16+ | Best size, slower encode |
| GIF | Lossless (indexed) | 1-bit only | Yes | Universal | Legacy only |
Frequently asked questions
Is WebP supported everywhere?
Yes, in all modern browsers. Chrome, Firefox, Safari, and Edge have all supported WebP since 2020 or earlier. The only notable gap was iOS Safari before iOS 14 (2020). If your users are on modern devices, WebP is safe to use without a fallback.
Does WebP support transparency?
Yes. WebP supports 8-bit alpha in both lossy and lossless modes — the same full-range transparency you get with PNG. JPEG has no alpha channel at all, so WebP is the best lossy format when transparency is required.
Does WebP support animation?
Yes. Animated WebP is supported in all modern browsers and produces significantly smaller files than GIF — often 5–10× smaller for the same animation. For very short simple loops, GIF still has near-universal email client support, which animated WebP lacks.
Is WebP better than JPEG?
For web delivery, yes — WebP is typically 25–35% smaller than JPEG at equivalent visual quality. It also supports transparency and animation, which JPEG does not. The only reason to prefer JPEG today is when you need maximum compatibility with legacy systems, print workflows, or email clients that do not accept WebP.
How do I convert a WebP to JPG?
Use the WebP to JPG converter on this site. Upload your WebP file, choose quality, and download the result. Converting from WebP to JPG is lossy-to-lossy, so each conversion pass slightly reduces quality — convert directly from your original source file whenever possible.
Should I use lossy or lossless WebP?
Use lossy WebP for photographs and complex imagery — it produces dramatically smaller files with minimal visible quality loss. Use lossless WebP for screenshots, UI graphics, logos, and text-heavy images where every pixel must be exact. Lossless WebP still beats PNG on file size in most cases.
What is the best WebP quality setting?
For lossy WebP, 80–85 is a strong default for web delivery. WebP at 80 typically looks as sharp as JPEG at 90. Use 85–90 for hero images or product photos where fine detail matters. Drop to 70–75 for thumbnails or images that will be viewed at small sizes.