Free webp to jpg
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Image MIME Reference
GIF

Graphics Interchange Format

image/gif
VS

Portable Bitmap

image/x-portable-bitmap
PBM

A complete technical comparison of Graphics Interchange Format and Portable Bitmap — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

GIF wins on browser support

Feature Support

Feature GIF PBM
Transparency (Alpha) Yes ✕ No
Animation Support Yes ✕ No
Progressive Loading Yes ✕ No
HDR Support ✕ No ✕ No
EXIF Metadata ✕ No ✕ No
ICC Color Profile Yes ✕ No
Graphics Interchange Format
image/gif
Extension
.gif
Container GIF
Compression Lossless (LZW)
Algorithm
LZW (Lempel-Ziv-Welch)
Color Depth 1-bit, 4-bit, 8-bit (Indexed)
Developed by CompuServe
Released 1987
Magic Bytes
47 49 46 38 39 61
Full GIF reference →
Portable Bitmap
image/x-portable-bitmap
Extension
.pbm
Container Netpbm
Compression Uncompressed
Algorithm
None
Color Depth 1-bit (Monochrome)
Developed by Jef Poskanzer (Netpbm Project)
Released 1988
Magic Bytes
50 31 (ASCII) or 50 34 (Binary)
Full PBM reference →

Browser Support Comparison

Browser GIF PBM
Chrome Chrome
✓ All
 ✕
Firefox Firefox
✓ All
 ✕
Safari Safari
✓ All
 ✕
Edge Edge
✓ All
 ✕
IE IE (Legacy)
✓
 ✕
GIF

GIF Strengths

  • Universal support across all web browsers, operating systems, and messaging apps
  • Supports basic frame-by-frame animation out of the box
  • Lossless compression is highly effective for simple, flat-color graphics like logos or pixel art
Limitations
  • Limited to 256 colors per frame, resulting in poor quality for complex gradients and photographs
  • Animations produce massive file sizes compared to modern formats like MP4, WebP, or AVIF
  • 1-bit transparency limits edge blending on non-uniform backgrounds
PBM

PBM Strengths

  • Absolute structural simplicity allows parsers to be written from scratch with just a few lines of code
  • ASCII encoding allows manual editing and debugging directly within a standard text editor
  • Serves as a flawless, lossless intermediary for 1-bit raster data like scanned documents or barcodes
Limitations
  • Strictly limited to 1-bit monochrome images; cannot natively display shades of gray or color
  • Lack of compression results in extremely large file sizes, particularly when using the ASCII 'P1' encoding
  • No support for alpha transparency or modern metadata standards like EXIF

When to choose which format

GIF
Use GIF when…
  • Web Animations
  • Memes
  • Simple Graphics
  • Logos with flat colors
PBM
Use PBM when…
  • Optical Character Recognition (OCR) Pre-processing
  • Unix/Linux Command-Line Image Pipelines
  • Academic Image Processing Teaching

More comparisons

GIF vs ACES → PBM vs ACES → GIF vs APNG → PBM vs APNG → GIF vs AVCI → PBM vs AVCI → GIF vs AVCS → PBM vs AVCS → GIF vs AVIF → PBM vs AVIF → All comparisons →
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