Free webp to jpg
Image MIME Reference
FLIF

Free Lossless Image Format

image/flif
VS

JPEG 2000 Part 2 (Extended)

image/jpx
JPX

A complete technical comparison of Free Lossless Image Format and JPEG 2000 Part 2 (Extended) — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

Equal browser support

Feature Support

Feature FLIF JPX
Transparency (Alpha) Yes Yes
Animation Support Yes Yes
Progressive Loading Yes Yes
HDR Support Yes Yes
EXIF Metadata Yes Yes
ICC Color Profile Yes Yes
Free Lossless Image Format
image/flif
Extension
.flif
Container FLIF Bitstream
Compression Lossless (MANIAC Entropy Coding)
Algorithm
MANIAC (Meta-Adaptive Near-zero Integer Arithmetic Coding)
Color Depth 1-bit to 16-bit (Per Channel), Grayscale, RGB, RGBA, CMYK
Developed by Jon Sneyers and Pieter Wuille (Cloudinary)
Released 2015
Magic Bytes
46 4C 49 46
Full FLIF reference →
JPEG 2000 Part 2 (Extended)
image/jpx
Extension
.jpx.jpf
Container ISOBMFF / JPX (ISO/IEC 15444-2)
Compression Lossy / Lossless
Algorithm
Discrete Wavelet Transform (DWT)
Color Depth 8-bit, 16-bit, 32-bit, 38-bit
Developed by Joint Photographic Experts Group (JPEG)
Released 2002
Magic Bytes
00 00 00 0C 6A 50 20 20 0D 0A 87 0A ... 66 74 79 70 6A 70 78 20
Full JPX reference →

Browser Support Comparison

Browser FLIF JPX
Chrome Chrome
Firefox Firefox
Safari Safari
Edge Edge
IE IE (Legacy)
FLIF

FLIF Strengths

  • Achieves some of the highest lossless compression ratios ever developed for raster images
  • Incredible progressive decoding allows an image to be highly recognizable even after only 5% of the file has been downloaded
  • Supports animations and complex alpha channels losslessly
Limitations
  • Officially abandoned in favor of JPEG XL
  • Zero native support in web browsers or standard operating system previewers
  • Encoding speed can be significantly slower than standard PNG or WebP compression
JPX

JPX Strengths

  • Removes the color space limitations of baseline JP2, adding native support for CMYK, CIE Lab, and custom vendor color spaces
  • Supports multiple codestreams in a single file, allowing for rich compositing and animation
  • Enables fragmented files where image data and metadata can reside in separate physical files via data references
Limitations
  • Extremely complex specification makes full software implementation rare, leading to compatibility issues
  • Zero web browser support, rendering it unsuitable for public internet distribution
  • Often overkill for standard imaging tasks where baseline JP2 or modern alternatives like AVIF suffice

When to choose which format

FLIF
Use FLIF when…
  • Archival of Uncompressed Image Assets
  • Bandwidth-Constrained Progressive Image Loading (Historical)
  • Medical and Scientific Imaging Storage
JPX
Use JPX when…
  • Prepress & Commercial Printing (CMYK)
  • Geospatial Data
  • Archival Preservation
  • Medical Imaging
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