Free webp to jpg
EN
Image MIME Reference
PBM

Portable Bitmap

image/x-portable-bitmap
VS

WebP Image

image/webp
WebP

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

WebP wins on browser support

Feature Support

Feature PBM WebP
Transparency (Alpha) ✕ No Yes
Animation Support ✕ No Yes
Progressive Loading ✕ No ✕ No
HDR Support ✕ No ✕ No
EXIF Metadata ✕ No Yes
ICC Color Profile ✕ No Yes
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 →
WebP Image
image/webp
Extension
.webp
Container RIFF
Compression Lossy / Lossless
Algorithm
VP8VP8L
Color Depth 8-bit
Developed by Google
Released 2010
Magic Bytes
52 49 46 46 XX XX XX XX 57 45 42 50
Full WebP reference →

Browser Support Comparison

Browser PBM WebP
Chrome Chrome
✕
✓ 32+
Firefox Firefox
✕
✓ 65+
Safari Safari
✕
✓ 14+
Edge Edge
✕
✓ 18+
IE IE (Legacy)
✕ ✕
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
WebP

WebP Strengths

  • Superior lossy compression — 25–35% smaller than JPEG at equivalent quality
  • Supports both animation and full alpha transparency
  • Lossless mode available with smaller file sizes than PNG
Limitations
  • Slower encoding than JPEG, especially for lossless
  • Not supported in Internet Explorer or very old browsers

When to choose which format

PBM
Use PBM when…
  • Optical Character Recognition (OCR) Pre-processing
  • Unix/Linux Command-Line Image Pipelines
  • Academic Image Processing Teaching
WebP
Use WebP when…
  • Websites
  • Ecommerce
  • Mobile Apps
  • CMS Images

More comparisons

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