Image MIME Reference
PCX
PiCture eXchange
image/x-pcx
VS
Truevision TGA (Legacy MIME Alias)
image/x-tga
TGA
A complete technical comparison of PiCture eXchange and Truevision TGA (Legacy MIME Alias) — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | PCX | TGA |
|---|---|---|
| Transparency (Alpha) | ✕ No | Yes |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | ✕ No | ✕ No |
| EXIF Metadata | ✕ No | ✕ No |
| ICC Color Profile | ✕ No | ✕ No |
PiCture eXchange
image/x-pcx
Extension
.pcx
Container
ZSoft Proprietary Header (128 bytes)
Compression
Run-Length Encoding (RLE)
Algorithm
ZSoft RLE
Color Depth
1-bit (Monochrome), 4-bit (16 colors), 8-bit (256 colors), 24-bit (True Color)
Developed by
ZSoft Corporation
Released
1985
Magic Bytes
0A (followed by version, e.g., 0A 05 01 08)
Truevision TGA (Legacy MIME Alias)
image/x-tga
Extension
.tga.icb.vda.vst
Container
Truevision TGA Footer/Header
Compression
Uncompressed / Run-Length Encoding (RLE)
Algorithm
NoneRLE
Color Depth
8-bit (Grayscale or Indexed), 16-bit (High Color), 24-bit (True Color), 32-bit (True Color with Alpha Channel)
Developed by
Truevision Inc.
Released
1984
Magic Bytes
54 52 55 45 56 49 53 49 4F 4E 2D 58 46 49 4C 45 2E 00 (At the end of the file)
Browser Support Comparison
| Browser | PCX | TGA |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
PCX
PCX Strengths
- Incredibly simple RLE algorithm makes it very fast to decode, which was historically vital for early 3D video game engines
- Retains crisp, lossless pixel data suitable for pixel art and interface assets
- Well-documented and highly supported by older desktop publishing and image editing software
Limitations
- Extremely inefficient compression by modern standards, producing large file sizes compared to PNG
- Lacks modern imaging features such as alpha channel transparency, EXIF metadata, and color profiles
- Zero support in web browsers; must be converted to PNG for web use
TGA
TGA Strengths
- Incredibly simple byte layout allows developers to write custom loaders and exporters in a few dozen lines of code, bypassing the need for heavy external libraries
- Native support for 8-bit alpha channels ensures flawless transparency masking for real-time 3D rendering
- Fast, predictable RLE decoding requires almost no CPU overhead compared to DEFLATE (PNG) or DCT (JPEG)
Limitations
- RLE compression is relatively weak by modern standards, resulting in large file sizes
- Lacks a standard magic byte header at the beginning of the file, making file-sniffing unreliable for older v1.0 files
- Zero support in web browsers; must be converted to PNG or WebP for web delivery
When to choose which format
PCX
Use PCX when…
- MS-DOS and Early Windows Graphics
- 1990s Video Game Assets (Textures, UI)
- Retro Computing Archival
TGA
Use TGA when…
- Video Game 3D Textures and Materials
- 3D Rendering and Animation Sequences
- Legacy Video Production Workflows