Free webp to jpg
Image MIME Reference
BMP

Windows Bitmap (Legacy Windows MIME Alias)

image/x-windows-bmp
VS

JPEG XR Image Sequence (HEIF Container)

image/jxrs
JPEG-XR-Sequence

A complete technical comparison of Windows Bitmap (Legacy Windows MIME Alias) and JPEG XR Image Sequence (HEIF Container) — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

BMP wins on browser support

Feature Support

Feature BMP JPEG-XR-Sequence
Transparency (Alpha) Yes Yes
Animation Support ✕ No Yes
Progressive Loading ✕ No Yes
HDR Support ✕ No Yes
EXIF Metadata ✕ No Yes
ICC Color Profile Yes Yes
Windows Bitmap (Legacy Windows MIME Alias)
image/x-windows-bmp
Extension
.bmp.dib
Container DIB (Device-Independent Bitmap)
Compression Uncompressed / Run-Length Encoding (RLE)
Algorithm
NoneRLE4RLE8
Color Depth 1-bit (Monochrome), 4-bit (16 colors), 8-bit (256 colors), 16-bit (High Color), 24-bit (True Color), 32-bit (True Color with Alpha)
Developed by Microsoft Corporation
Released 1985
Magic Bytes
42 4D
Full BMP reference →
JPEG XR Image Sequence (HEIF Container)
image/jxrs
Extension
.jxrs
Container HEIF / ISOBMFF (ISO/IEC 23008-12 / Annex F of ITU-T T.832)
Compression Lossy / Lossless
Algorithm
JPEG XR (Lapped Biorthogonal Transform)
Color Depth 8-bit, 16-bit, 32-bit (Float)
Developed by ISO/IEC JTC 1 / ITU-T
Released 2019
Magic Bytes
XX XX XX XX 66 74 79 70 6A 78 72 53
Full JPEG-XR-Sequence reference →

Browser Support Comparison

Browser BMP JPEG-XR-Sequence
Chrome Chrome
✓ 1
Firefox Firefox
✓ 1
Safari Safari
✓ 1
Edge Edge
✓ 12
IE IE (Legacy)
BMP

BMP Strengths

  • Universally supported by all major operating systems and modern web browsers
  • Maintains perfect, lossless fidelity because pixel data is stored without lossy compression artifacts
Limitations
  • Massive file size overhead due to a lack of modern compression algorithms
  • Legacy MIME strings like 'image/x-windows-bmp' can trigger validation warnings in strict security or API environments if unhandled
JPEG-XR-Sequence

JPEG-XR-Sequence Strengths

  • Supports 32-bit floating point HDR color depths natively across an entire animation sequence
  • Combines the advanced coding efficiencies of JPEG XR with the sequence timing and metadata framework of HEIF
  • Shares frame data structures allowing for optimized storage of burst photography
Limitations
  • Extremely rare format with essentially no mainstream software adoption
  • Zero web browser support
  • Overshadowed heavily by HEVC (HEIC sequences) and AV1 (AVIF sequences) which offer superior compression and broader hardware decoding support

When to choose which format

BMP
Use BMP when…
  • Legacy Windows Desktop Registry Associations
  • Older Enterprise Intranet Applications
  • Windows Graphics Archival
JPEG-XR-Sequence
Use JPEG-XR-Sequence when…
  • Experimental Animation Workflows
  • HDR Burst Photography Archiving
  • Specialized Medical & Scientific Imaging
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