Image MIME Reference
JPEG-XS-(HEIF)
JPEG XS Image (HEIF Container)
image/jxsi
VS
Khronos Texture
image/ktx
KTX
A complete technical comparison of JPEG XS Image (HEIF Container) and Khronos Texture — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | JPEG-XS-(HEIF) | KTX |
|---|---|---|
| Transparency (Alpha) | Yes | Yes |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | Yes | Yes |
| EXIF Metadata | Yes | ✕ No |
| ICC Color Profile | Yes | ✕ No |
JPEG XS Image (HEIF Container)
image/jxsi
Extension
.jxsi.jxs.hif
Container
HEIF / ISOBMFF (ISO/IEC 23008-12)
Compression
Lossy (Visually Lossless) / Mathematically Lossless
Algorithm
JPEG XS (ISO/IEC 21122-1)
Color Depth
8-bit, 10-bit, 12-bit, 14-bit, 16-bit
Developed by
Joint Photographic Experts Group (JPEG)
Released
2019
Magic Bytes
XX XX XX XX 66 74 79 70 6A 78 73 69
Khronos Texture
image/ktx
Extension
.ktx
Container
KTX (Khronos Texture 1.1)
Compression
Uncompressed / GPU Compressed (ASTC, ETC, BCn, PVRTC)
Algorithm
ASTCETC1 / ETC2BCn (DXT)PVRTCBasis Universal (in KTX2)
Color Depth
8-bit, 16-bit, 32-bit (Integer/Float)
Developed by
Khronos Group
Released
2010
Magic Bytes
AB 4B 54 58 20 31 31 BB 0D 0A 1A 0A
Browser Support Comparison
| Browser | JPEG-XS-(HEIF) | KTX |
|---|---|---|
|
|
✕ | ✕ |
|
|
✕ | ✕ |
|
|
✕ | ✕ |
|
|
✕ | ✕ |
|
|
✕ | ✕ |
JPEG-XS-(HEIF)
JPEG-XS-(HEIF) Strengths
- Provides sub-millisecond encoding and decoding latency while retaining visually lossless quality
- Brings the extensive metadata, EXIF, XMP, and color-profiling capabilities of the HEIF container to JPEG XS
- Allows grouping of multiple high-quality JPEG XS frames into a single collection file
Limitations
- Zero web browser compatibility, limiting it entirely to professional and industrial hardware workflows
- Extremely niche adoption compared to standard HEVC-based HEIC or raw JPEG XS codestreams
- Requires custom parsing logic to extract the JPEG XS codestream from the HEIF boxes
KTX
KTX Strengths
- Enables direct-to-GPU texture uploading, drastically reducing load times and CPU overhead in 3D applications
- Supports complex texture types natively (mipmaps, cubemaps, 3D volumes, texture arrays)
- Standardized across major Khronos APIs (OpenGL, Vulkan, WebGL) unlike vendor-specific formats like DDS
Limitations
- Requires custom JavaScript loaders to parse and display on the web
- Zero native support in consumer image viewers or 2D photo editing software
- Format fragmentation: a KTX file containing an ASTC payload will fail to render on hardware that only supports BCn compression (KTX2 and Basis Universal solve this)
When to choose which format
JPEG-XS-(HEIF)
Use JPEG-XS-(HEIF) when…
- Live Broadcast Infrastructure
- Medical Imaging & Archival
- Video over IP Networks
- Automotive & Drone Systems
KTX
Use KTX when…
- Real-time 3D Graphics
- WebGL / WebGPU Applications
- Mobile Games
- Virtual/Augmented Reality (VR/AR)