Free webp to jpg
EN
Image MIME Reference
JPM

JPEG 2000 Compound Image File Format

image/jpm
VS

WebP Image

image/webp
WebP

A complete technical comparison of JPEG 2000 Compound Image File Format 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 JPM WebP
Transparency (Alpha) Yes Yes
Animation Support ✕ No Yes
Progressive Loading Yes ✕ No
HDR Support ✕ No ✕ No
EXIF Metadata Yes Yes
ICC Color Profile Yes Yes
JPEG 2000 Compound Image File Format
image/jpm
Extension
.jpm.jpgm
Container ISOBMFF / JPM (ISO/IEC 15444-6)
Compression Lossy / Lossless / Mixed Raster Content (MRC)
Algorithm
JPEG 2000JBIG2JPEGMMR
Color Depth 1-bit (Text/Masks), 8-bit, 16-bit, 24-bit
Developed by Joint Photographic Experts Group (JPEG)
Released 2003
Magic Bytes
00 00 00 0C 6A 50 20 20 0D 0A 87 0A ... 66 74 79 70 6A 70 6D 20
Full JPM 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 JPM WebP
Chrome Chrome
✕
✓ 32+
Firefox Firefox
✕
✓ 65+
Safari Safari
✕
✓ 14+
Edge Edge
✕
✓ 18+
IE IE (Legacy)
✕ ✕
JPM

JPM Strengths

  • Highly optimized for scanned documents, drastically reducing file sizes without sacrificing the readability of text or the quality of embedded photos
  • Supports multi-page documents within a single file
  • Object-based architecture allows for complex layout representation and independent extraction of elements
Limitations
  • Failed to achieve widespread adoption, largely being overshadowed by PDF/A and DjVu
  • Zero native web browser compatibility
  • Requires complex, specialized software to properly encode and decode the multi-layered MRC structure
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

JPM
Use JPM when…
  • Scanned Document Archiving
  • Mixed Raster Content (MRC) Imaging
  • Digital Libraries
WebP
Use WebP when…
  • Websites
  • Ecommerce
  • Mobile Apps
  • CMS Images

More comparisons

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