Image MIME Reference
Sony-ARW
Sony Alpha Raw Image
image/x-sony-arw
VS
WebP Image
image/webp
WebP
A complete technical comparison of Sony Alpha Raw Image and WebP Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
WebP wins on browser support
Feature Support
| Feature | Sony-ARW | WebP |
|---|---|---|
| Transparency (Alpha) | ✕ No | Yes |
| Animation Support | ✕ No | Yes |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | Yes | ✕ No |
| EXIF Metadata | Yes | Yes |
| ICC Color Profile | Yes | Yes |
Sony Alpha Raw Image
image/x-sony-arw
Extension
.arw
Container
TIFF-based (Proprietary)
Compression
Uncompressed / Lossless Compressed / Lossy Compressed
Algorithm
NoneSony Proprietary LosslessSony Proprietary Lossy
Color Depth
12-bit (Per Channel), 14-bit (Per Channel)
Developed by
Sony Corporation
Released
2006
Magic Bytes
49 49 2A 00
WebP Image
image/webp
Extension
.webp
Container
RIFF
Compression
Lossy / Lossless
Algorithm
VP8VP8L
Color Depth
8-bit
Developed by
Google
Released
2010
Magic Bytes
52 49 46 46 XX XX XX XX 57 45 42 50
Browser Support Comparison
| Browser | Sony-ARW | WebP |
|---|---|---|
Chrome
|
✕ |
✓ 32+
|
Firefox
|
✕ |
✓ 65+
|
Safari
|
✕ |
✓ 14+
|
Edge
|
✕ |
✓ 18+
|
IE (Legacy)
|
✕ | ✕ |
Sony-ARW
Sony-ARW Strengths
- Retains absolute maximum sensor data, enabling massive shadow recovery and highlight protection compared to compressed in-camera JPEGs
- Embeds high-quality JPEG previews and robust metadata, allowing photographers to match in-camera color science (like Creative Looks) perfectly during raw processing
- Utilizes the standard TIFF container structure, ensuring broad compatibility with open-source decoding libraries (like LibRaw)
Limitations
- Proprietary format means it requires constant updates to raw processing engines every time Sony releases a new camera model
- Sony's historically controversial lossy compression algorithm (often called 'star eater' due to spatial filtering artifacts) was a drawback for astrophotography in older ARW versions, though largely resolved in newer models with uncompressed/lossless options
- Cannot be directly embedded into web pages or used in standard HTML/CSS contexts
WebP
WebP Strengths
- Superior lossy compression — 25–35% smaller than JPEG at equivalent quality
- Supports both animation and full alpha transparency
- Lossless mode available with smaller file sizes than PNG
Limitations
- Slower encoding than JPEG, especially for lossless
- Not supported in Internet Explorer or very old browsers
When to choose which format
Sony-ARW
Use Sony-ARW when…
- Professional Digital Photography
- Non-destructive Image Post-Processing
- High Dynamic Range (HDR) Imaging Archival
WebP
Use WebP when…
- Websites
- Ecommerce
- Mobile Apps
- CMS Images