Free webp to jpg
Image MIME Reference
NAPLPS

North American Presentation Level Protocol Syntax

image/naplps
VS

Adobe Photoshop Document

image/vnd.adobe.photoshop
PSD

A complete technical comparison of North American Presentation Level Protocol Syntax and Adobe Photoshop Document — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

Equal browser support

Feature Support

Feature NAPLPS PSD
Transparency (Alpha) ✕ No Yes
Animation Support Yes Yes
Progressive Loading Yes ✕ No
HDR Support ✕ No Yes
EXIF Metadata ✕ No Yes
ICC Color Profile ✕ No Yes
North American Presentation Level Protocol Syntax
image/naplps
Extension
.nap.naplps
Container NAPLPS Byte Stream
Compression Uncompressed (Tokenized ASCII Commands)
Algorithm
None (Coordinate encoding)
Color Depth 16-color palette (Indexed from larger color spaces)
Developed by ANSI / CSA (Based on Canadian CRC's Telidon)
Released 1983
Magic Bytes
1B (Variable / ESC sequences)
Full NAPLPS reference →
Adobe Photoshop Document
image/vnd.adobe.photoshop
Extension
.psd.psb.pdd
Container Adobe Photoshop Document (PSD/PSB)
Compression Uncompressed / RLE (Run-Length Encoding) / ZIP
Algorithm
RLEZIP (with or without prediction)None
Color Depth 1-bit (Bitmap), 8-bit, 16-bit, 32-bit (Float/HDR)
Developed by Adobe Systems
Released 1990
Magic Bytes
38 42 50 53
Full PSD reference →

Browser Support Comparison

Browser NAPLPS PSD
Chrome Chrome
Firefox Firefox
Safari Safari
Edge Edge
IE IE (Legacy)
NAPLPS

NAPLPS Strengths

  • Extremely bandwidth-efficient, enabling colorful graphical interfaces over early 300 baud dial-up connections
  • Resolution-independent vector scaling allowed the exact same file to be displayed accurately on varied early PC monitors and television sets
Limitations
  • Completely obsolete and unsupported by modern web technologies
  • Relies heavily on stateful parsing and terminal emulators rather than straightforward file decoding
  • Easily misidentified by MIME sniffers as plain text or generic binary streams due to the lack of a standardized file header
PSD

PSD Strengths

  • The undisputed global standard for layered raster graphics and non-destructive image editing
  • Supports incredibly complex compositions combining raster data, vector shapes, live text, and adjustment layers
  • Full support for advanced color spaces (CMYK, Lab, multi-channel) and 32-bit floating-point HDR workflows
Limitations
  • Proprietary format: while the specification is published, complete feature-parity is rarely achieved by third-party software (e.g., smart objects and complex layer styles often break)
  • Files can reach enormous sizes (gigabytes) due to the preservation of unflattened, high-resolution layer data
  • Zero support for native rendering in web browsers or standard mobile image viewers

When to choose which format

NAPLPS
Use NAPLPS when…
  • 1980s Videotex Services
  • Prodigy Online Service Graphics
  • Historical BBS Terminal Graphics
  • Legacy Teletext Broadcasts
PSD
Use PSD when…
  • Professional Photo Retouching
  • Digital Painting and Illustration
  • UI/UX Design Workflows
  • Graphic Design and Print Production
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