Free webp to jpg
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Image MIME Reference
BMP

Windows Bitmap (Legacy Windows MIME Alias)

image/x-windows-bmp
VS

GIMP Image Format

image/x-xcf
XCF

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

BMP wins on browser support

Feature Support

Feature BMP XCF
Transparency (Alpha) Yes Yes
Animation Support ✕ No Yes
Progressive Loading ✕ No ✕ No
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 →
GIMP Image Format
image/x-xcf
Extension
.xcf
Container GIMP Hierarchical Chunk Container
Compression None / RLE (Run-Length Encoding) / Zlib / Deflate (In newer GIMP versions)
Algorithm
NoneRLEZlib
Color Depth 8-bit per channel, 16-bit per channel, 32-bit floating point
Developed by Spencer Kimball, Peter Mattis, and the GIMP Development Team
Released 1995
Magic Bytes
67 69 6D 70 20 78 63 66
Full XCF reference →

Browser Support Comparison

Browser BMP XCF
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
XCF

XCF Strengths

  • Preserves all non-destructive editing elements, layer hierarchies, masks, and alpha channels across GIMP sessions
  • Open and thoroughly documented specification within the open-source community, allowing third-party tools like Krita and ImageMagick to read project files
  • Reliable magic byte header prevents misidentification
Limitations
  • Massive file sizes because raw, unflattened layer bitmaps and masks are stored directly within the project archive
  • Completely proprietary to the GIMP ecosystem for deep editing; cannot be natively rendered or parsed by web browsers
  • Third-party software supporting XCF may occasionally struggle to render complex text layer adjustments or advanced layer blend modes identically to GIMP

When to choose which format

BMP
Use BMP when…
  • Legacy Windows Desktop Registry Associations
  • Older Enterprise Intranet Applications
  • Windows Graphics Archival
XCF
Use XCF when…
  • GIMP Native Project Archival
  • Layered Photo Editing and Graphic Design
  • Intermediary Asset Preparation for Export

More comparisons

BMP vs ACES → XCF vs ACES → BMP vs APNG → XCF vs APNG → BMP vs AVCI → XCF vs AVCI → BMP vs AVCS → XCF vs AVCS → BMP vs AVIF → XCF vs AVIF → All comparisons →
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