Image MIME Reference
FPX
FlashPix
image/vnd.fpx
VS
High Efficiency Image Container
image/heic
HEIC
A complete technical comparison of FlashPix and High Efficiency Image Container — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
HEIC wins on browser support
Feature Support
| Feature | FPX | HEIC |
|---|---|---|
| Transparency (Alpha) | Yes | Yes |
| Animation Support | ✕ No | Yes |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | ✕ No | Yes |
| EXIF Metadata | Yes | Yes |
| ICC Color Profile | Yes | Yes |
FlashPix
image/vnd.fpx
Extension
.fpx
Container
Microsoft OLE Structured Storage (COM)
Compression
JPEG (Lossy) / Uncompressed / Single-color (Solid)
Algorithm
JPEGNone
Color Depth
8-bit (Grayscale/Indexed), 24-bit (RGB), 32-bit (CMYK/RGBA)
Developed by
Eastman Kodak, Microsoft, Hewlett-Packard, Live Picture
Released
1996
Magic Bytes
D0 CF 11 E0 A1 B1 1A E1
High Efficiency Image Container
image/heic
Extension
.heic
Container
HEIF / ISOBMFF
Compression
Lossy / Lossless
Algorithm
HEVC (H.265)
Color Depth
8-bit, 10-bit, 12-bit, 16-bit
Developed by
MPEG (Standard) / Apple (Adoption)
Released
2017
Magic Bytes
XX XX XX XX 66 74 79 70 68 65 69 63
Browser Support Comparison
| Browser | FPX | HEIC |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ |
✓ 11+
|
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
FPX
FPX Strengths
- Allowed early, low-RAM computers to view and edit massive, high-resolution digital photos instantly by only loading the needed tiles and resolutions
- Pioneered the multi-resolution pyramid and tiling concepts heavily used today in modern deep-zoom and web mapping applications (like Google Maps)
Limitations
- Completely obsolete and unsupported by modern web browsers or operating systems
- Uses the complex, proprietary Microsoft OLE container format, making it incredibly difficult to parse or extract data from without dedicated legacy libraries
- Prone to being misidentified by MIME sniffers as an old Microsoft Office document
HEIC
HEIC Strengths
- Exceptional compression efficiency — stores images at roughly half the file size of JPEG with equal or better visual quality
- Natively supports modern photography features like depth maps, 16-bit color, HDR, and alpha channel transparency
- Can store image bursts, focal stacks, and animations (Live Photos) within a single file
Limitations
- Heavily encumbered by software patents, leading to very poor adoption outside the Apple ecosystem
- Not supported by standard web browsers (except Safari), requiring server-side or client-side conversion for web delivery
- Windows requires downloading a separate (often paid) extension from the Microsoft Store to view natively
When to choose which format
FPX
Use FPX when…
- Legacy Digital Photography
- Kodak Picture CDs (Historical)
- Early High-Resolution Image Viewers
HEIC
Use HEIC when…
- iOS / iPhone Photography
- macOS Ecosystem
- High-Quality Image Archiving