Free webp to jpg
EN
Image MIME Reference
JPEG

JPEG Image

image/jpeg
VS

Portable Bitmap

image/x-portable-bitmap
PBM

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

JPEG wins on browser support

Feature Support

Feature JPEG PBM
Transparency (Alpha) ✕ No ✕ No
Animation Support ✕ No ✕ No
Progressive Loading Yes ✕ No
HDR Support ✕ No ✕ No
EXIF Metadata Yes ✕ No
ICC Color Profile Yes ✕ No
JPEG Image
image/jpeg
Extension
.jpg.jpeg.jpe.jfif
Container JFIF / Exif
Compression Lossy
Algorithm
DCT (Discrete Cosine Transform)
Color Depth 8-bit
Developed by Joint Photographic Experts Group
Released 1992
Magic Bytes
FF D8 FF
Full JPEG 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 JPEG PBM
Chrome Chrome
✓ All
 ✕
Firefox Firefox
✓ All
 ✕
Safari Safari
✓ All
 ✕
Edge Edge
✓ All
 ✕
IE IE (Legacy)
✓
 ✕
JPEG

JPEG Strengths

  • Universal support — every browser, OS, and application handles JPEG
  • Excellent compression for complex photographs with natural color gradients
  • Rich metadata support: EXIF (GPS, camera settings), ICC color profiles
Limitations
  • No transparency — cannot have a transparent background
  • Lossy compression introduces visible artifacts on sharp edges and text
  • No animation support
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

JPEG
Use JPEG when…
  • Photography
  • Websites
  • Social Media
  • Print
PBM
Use PBM when…
  • Optical Character Recognition (OCR) Pre-processing
  • Unix/Linux Command-Line Image Pipelines
  • Academic Image Processing Teaching

More comparisons

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