Free webp to jpg
Image MIME Reference
BMP

Windows Bitmap (Legacy Windows MIME Alias)

image/x-windows-bmp
VS

Adobe Photoshop Document

image/vnd.adobe.photoshop
PSD

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

BMP wins on browser support

Feature Support

Feature BMP PSD
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 →
Adobe Photoshop Document
image/vnd.adobe.photoshop
Extension
.psd.psb.pdd
Container Adobe Photoshop Document (PSD/PSB)
Compression Uncompressed / RLE (Run-Length Encoding) / ZIP
Algorithm
RLEZIP (with or without prediction)None
Color Depth 1-bit (Bitmap), 8-bit, 16-bit, 32-bit (Float/HDR)
Developed by Adobe Systems
Released 1990
Magic Bytes
38 42 50 53
Full PSD reference →

Browser Support Comparison

Browser BMP PSD
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
PSD

PSD Strengths

  • The undisputed global standard for layered raster graphics and non-destructive image editing
  • Supports incredibly complex compositions combining raster data, vector shapes, live text, and adjustment layers
  • Full support for advanced color spaces (CMYK, Lab, multi-channel) and 32-bit floating-point HDR workflows
Limitations
  • Proprietary format: while the specification is published, complete feature-parity is rarely achieved by third-party software (e.g., smart objects and complex layer styles often break)
  • Files can reach enormous sizes (gigabytes) due to the preservation of unflattened, high-resolution layer data
  • Zero support for native rendering in web browsers or standard mobile image viewers

When to choose which format

BMP
Use BMP when…
  • Legacy Windows Desktop Registry Associations
  • Older Enterprise Intranet Applications
  • Windows Graphics Archival
PSD
Use PSD when…
  • Professional Photo Retouching
  • Digital Painting and Illustration
  • UI/UX Design Workflows
  • Graphic Design and Print Production
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