Image MIME Reference
HEIC-Sequence
HEVC Image Sequence (HEIF Container)
image/heic-sequence
VS
Wireless Bitmap
image/vnd.wap.wbmp
WBMP
A complete technical comparison of HEVC Image Sequence (HEIF Container) and Wireless Bitmap — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
HEIC-Sequence wins on browser support
Feature Support
| Feature | HEIC-Sequence | WBMP |
|---|---|---|
| Transparency (Alpha) | Yes | ✕ No |
| Animation Support | Yes | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | Yes | ✕ No |
| EXIF Metadata | Yes | ✕ No |
| ICC Color Profile | Yes | ✕ No |
HEVC Image Sequence (HEIF Container)
image/heic-sequence
Extension
.heics.heic
Container
HEIF / ISOBMFF (ISO/IEC 14496-12)
Compression
Lossy / Lossless
Algorithm
HEVC (H.265)
Color Depth
8-bit, 10-bit, 12-bit, 16-bit
Developed by
Moving Picture Experts Group (MPEG) / Apple
Released
2017
Magic Bytes
XX XX XX XX 66 74 79 70 68 65 76 63
Wireless Bitmap
image/vnd.wap.wbmp
Extension
.wbmp
Container
WBMP Type 0
Compression
Uncompressed
Algorithm
None
Color Depth
1-bit (Monochrome)
Developed by
WAP Forum (Now Open Mobile Alliance)
Released
1999
Magic Bytes
00 00
Browser Support Comparison
| Browser | HEIC-Sequence | WBMP |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✓ 11+
|
✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
HEIC-Sequence
HEIC-Sequence Strengths
- Incredibly efficient storage for bursts and short animations compared to GIF or motion JPEG
- Supports 16-bit color, HDR, and alpha channel transparency across all frames
- Shares frame data blocks, meaning the base image and animation data are heavily optimized for space
Limitations
- Zero support in web browsers outside the Apple ecosystem (Chrome, Firefox, Edge do not support it)
- Heavily encumbered by HEVC patent pools, hindering open-source adoption
- Complex container structure makes parsing and decoding difficult without specialized libraries
WBMP
WBMP Strengths
- Extremely low processing overhead made it perfectly suited for the ultra-low-power CPUs of late 1990s mobile devices
- Tightly integrated into the WML (Wireless Markup Language) stack, enabling the first functional mobile internet experiences
Limitations
- Completely obsolete and lacks support in modern operating systems and browsers
- Limited entirely to 1-bit black and white (0 for black, 1 for white) with zero support for grayscale, color, or transparency
- The lack of a strong file header signature makes automated MIME type detection highly unreliable
When to choose which format
HEIC-Sequence
Use HEIC-Sequence when…
- Apple Live Photos
- Burst Photography
- High-Quality Animations
- Cinemagraphs
WBMP
Use WBMP when…
- Legacy WML (Wireless Markup Language) Mobile Sites
- Early Mobile Phone Icons and Operator Logos
- Historical WAP Archival