What is the PAT file format?
The .pat file extension is used for bitmap images of patterns. .pat images are comprised of rectangular, tileable elements and can range from a few pixels to several hundred pixels per side. Two distinct formats share this extension: the GIMP .pat and the Adobe Photoshop .pat.
The GIMP variant is a binary file with the ASCII tag GPAT embedded at byte offset 20; it stores a single tileable raster image in grayscale or RGB/RGBA color at arbitrary dimensions. The Photoshop variant is Adobe's undocumented proprietary preset container - often internally tagged 8BPT - which can hold one or more named pattern presets, each with its own name and pixel data.
.pat files are used by many graphics programs for filling areas with patterns, usually to produce background textures and decorative surface effects. They have a variety of uses - from web design and print workflows to computer games and screensavers. In Photoshop, patterns are loaded via Edit › Define Pattern and applied through the Paint Bucket tool or the Pattern Overlay layer style. In GIMP, patterns live in the Patterns dockable dialog and are applied with the Bucket Fill or Clone tools.
Related preset formats used alongside .pat files include Photoshop brushes (.abr) and Photoshop gradients (.grd). Source artwork is often prepared as a PNG image before being defined as a repeating pattern.
Security & safety
RISK: LOWPAT image patterns are inert preset data (small bitmaps) and contain no executable code, so opening or installing one is low-risk. The only practical pitfalls are non-malicious: a Photoshop pattern won't load in GIMP (and vice versa), so a 'broken' .pat is usually just the wrong app's format, and some 'free pattern' sites bundle adware in their downloaders - get patterns from reputable sources and the apps from official sites.
Format details
in a nutshellFULL NAMEPhotoshop/GIMP Pattern File
DEVELOPERAdobe (Photoshop .pat) and The GIMP Team (GIMP .pat)since GIMP .pat: 1990s; Photoshop .pat: Adobe proprietary preset format
CATEGORYRaster Image Files
MIME TYPEapplication/octet-stream
TYPETileable bitmap pattern preset (binary)
STANDARDOpen · royalty-free
This extension is also used by…
- AutoCAD Hatch Pattern - Plain-text definition of repeating hatch lines (angle, spacing, dashes) used to fill regions in CAD drawings; incompatible with image patterns.
- Embroidery Design (various machines) - Some embroidery/sewing systems reuse .pat for stitch-pattern data.
Programs that open PAT files
Windows2 apps
Adobe Photoshop
Paid Edit > Presets > Preset Manager (or Window > Patterns), then Load the .pat. Use it via Edit > Fill > Pattern. 
GIMP
Open-source Copy the .pat into your GIMP 'patterns' folder (Edit > Preferences > Folders > Patterns), refresh, then pick it from the Patterns dialog. Free Photoshop alternative. 
macOS2 apps
Linux1 app
GIMP
Open-source Copy the .pat into ~/.config/GIMP/.../patterns (or the system patterns folder), refresh, and use from the Patterns dialog. Technical details
deep spec| Format type | Tileable bitmap pattern preset, stored in binary |
| Developer | Adobe Systems (Photoshop variant); The GIMP Team (GIMP variant) |
| MIME type | application/octet-stream |
| GIMP magic signature | ASCII "GPAT" at byte offset 20 |
| Photoshop internal tag | "8BPT" (undocumented Adobe proprietary) |
| GIMP header fields | Width, height (32-bit big-endian integers), bytes per pixel, null-terminated pattern name |
| Bit depth | 8 bits per channel (GIMP); 8 or 16 bits per channel (Photoshop) |
| Color modes (GIMP) | Grayscale (1 byte/pixel), RGB (3 bytes/pixel), or RGBA (4 bytes/pixel) |
| Pixel data encoding (GIMP) | Raw, uncompressed pixel rows - no compression layer |
| Multi-pattern container | Photoshop .pat bundles multiple named presets per file; GIMP .pat holds exactly one pattern |
| Endianness (GIMP) | Big-endian (network byte order) for all header integer fields |
| Pattern dimensions | Arbitrary size defined by 32-bit header integers; typical tiles range from 8×8 to 256×256 px |
| Photoshop loading method | Registered via Edit › Define Pattern; managed in the Photoshop Preset Manager |
| Photoshop pixel data compression | Pattern pixel data inside a Photoshop .pat may be RLE-compressed |
| Transparency support | GIMP .pat supports an alpha channel (RGBA mode); Photoshop patterns support transparency via alpha |
| Released | GIMP .pat: 1990s; Photoshop .pat: Adobe proprietary preset format |
| Open standard | Yes · royalty-free |
| Specification | developer.gimp.org |
PAT conversions
Possible
.PAT .PNGGUIDE
Yes, you can extract a PAT pattern tile as a PNG by loading it in GIMP (free) or Photoshop and exporting the…
How to convert
.PAT .BMPGUIDE
Yes, you can convert PAT to BMP - load the pattern in GIMP or Photoshop, then export the tile as a BMP file.
How to convert
.PAT .JPGGUIDE
Yes - open the PAT in GIMP (free) or Photoshop, then export the tile as JPG.
How to convert
Not possible
Community Q&A
asked by users
K
Frequently asked questions
How do I open a PAT file?
You don't open it as a document - you install it into your image editor's Patterns and use it as a fill. In Photoshop, Load it via Window > Patterns; in GIMP, drop it into the patterns folder and refresh, then pick it from the Patterns dialog.
How do I install a .pat pattern in Photoshop?
Open Window > Patterns (or Edit > Presets > Preset Manager), click the menu and choose Import/Load Patterns, and select the .pat. It then appears as a fill pattern under Edit > Fill > Pattern.
Can I use a Photoshop .pat in GIMP (or vice versa)?
Not directly - they are different formats. GIMP can import some Photoshop patterns via a plugin, and a GIMP .pat won't load in Photoshop. The reliable cross-app route is to export the pattern tile as a PNG and use that image.
How do I turn a .pat into a PNG or JPG?
Load the pattern in GIMP or Photoshop and export the tile: in GIMP, select the pattern and File > Export As PNG/JPG. A Photoshop .pat can contain several patterns, so fill a canvas with each and save them out individually.
Is a .pat file an image?
Effectively yes - a Photoshop/GIMP .pat contains a small tileable bitmap. It's stored as a preset rather than a standalone picture, but the content is image data you can export to PNG/JPG.
References
1Adobe - Manage patterns and presets in Photoshophelpx.adobe.com
2GIMP Pattern - Just Solve the File Format Problemjustsolve.archiveteam.org
