What is the PMG file format?
.pmg is a proprietary raster image format associated with "Paint Magic," a legacy painting program from the Commodore 64 era (circa 1985-1990). The format is extremely obscure, with no surviving public specification.
The file begins with a binary header. The most common variant starts with the byte 0x15 followed by the sequence 67 6D 50 (ASCII gmP), which appears to be a reversed marker for "PMg." A second observed variant uses 0x14 as the leading version byte. These signatures were determined by empirical file analysis rather than published documentation.
Given its origin on Commodore 8-bit hardware, .pmg files are expected to use big-endian byte order (Motorola heritage) and are constrained to standard Commodore 64 screen resolutions - 320×200 pixels (hires mode) or 160×200 pixels (multicolor mode) - with a palette of up to 16 colors drawn from the fixed C64 palette. File sizes are correspondingly small, typically between 5 KB and 64 KB. The compression scheme, if any, is undocumented.
Today .pmg files are of interest mainly in retrocomputing and digital preservation contexts. XnView MP has historically been reported to open them, though support in the current version (3.x) is unverified. Adobe Photoshop does not support the format natively. Anyone encountering a .pmg file outside a Commodore 64 archive should consider whether a different application may use the same extension for a different proprietary format.
Security & safety
RISK: LOWImage files pose minimal risk. The format is so obscure that malicious PMG files are virtually unknown. Standard image-viewer sandboxing applies.
Format details
in a nutshell- Pegasus Mail Folder Index - Pegasus Mail e-mail client uses .pmg as a mailbox group index file; completely unrelated to images.
- PageMaker Group File - Older Adobe PageMaker used .pmg for grouped object data in documents.
Programs that open PMG files
Windows1 app
XnView MP
Freemium Try File → Open with .pmg file; XnView supports hundreds of legacy formats. Success not guaranteed for all PMG variants. 
macOS1 app
XnView MP
Freemium Attempt to open the .pmg file; XnView MP is the best cross-platform option for obscure legacy images. 
Linux1 app
XnView MP
Freemium Open .pmg file directly; or try the ImageMagick 'identify' command to detect if ImageMagick recognizes the format. Technical details
deep spec| Format origin | "Paint Magic" painting software for Commodore 64 (circa 1985-1990); no public specification survives |
| Magic bytes (variant 1) | `15 67 6D 50` at offset 0 - version byte `0x15` followed by ASCII `gmP` |
| Magic bytes (variant 2) | `14 67 6D 50` at offset 0 - version byte `0x14`; approximately half of known files use each variant |
| Byte order | Big-endian (Motorola 6510/68000 CPU heritage) |
| Expected resolution | 320×200 px (hires mode) or 160×200 px (multicolor mode) - standard C64 screen modes |
| Color depth | 2-16 colors; constrained to the Commodore 64 fixed 16-color palette |
| Compression | Unknown; likely uncompressed bitmap or basic RLE - no documentation exists |
| Typical file size | 5 KB - 64 KB (consistent with Commodore-era resolution and color constraints) |
| Header structure | Version byte + `gmP` marker followed by image dimensions and pixel data; exact layout undocumented |
| Modern software support | XnView MP (community-reported; current v3.x support status unverified); no native OS support |
| Primary use today | Retrocomputing and digital archive preservation |
| Format identification risk | Other applications may use .pmg for unrelated proprietary formats sharing the same extension |
| Released | circa 1985-1990 (Commodore 64 era) |
PMG conversions
Community Q&A
asked by usersNo questions yet - be the first to ask about PMG files.
