What is the BAR file format?
.bar files are proprietary binary game data archives used by Ensemble Studios' real-time strategy game series. The format debuted with *Age of Mythology* in 2002 and later appeared in *Age of Empires III* (2005), *Age of Mythology: The Titans* (2003), *Age of Empires Online* (2011), and the 2024 remaster *Age of Mythology: Retold*.
Each .bar archive bundles game assets - textures, 3D models, sounds, music, maps, UI elements, and XML data files - into a single container that the game engine reads directly at runtime. Individual entries are compressed with zlib, though some are stored uncompressed. The format uses a little-endian binary layout with a header holding a file count and directory table; each entry records its filename, byte offset, compressed size, and uncompressed size.
Two main variants are known from community reverse engineering: the Age of Mythology variant (2002) and the Age of Empires III variant (2005); *Age of Mythology: Retold* introduced further updates. The format is undocumented by Microsoft. Third-party tools - including BAR Explorer, AoMED, and the Resource Manager for *Retold* - can extract archive contents for modding. The .pak format serves a similar role in other game engines.
Security & safety
RISK: LOWBAR files are read-only game data archives. They cannot execute code directly. Modded BAR files replacing game assets are safe; do not download BAR replacements from untrusted sources as they could replace game files with corrupted data.
Format details
in a nutshell- BlackBerry Application Archive - BlackBerry OS devices use .bar as the installation package format for BB10 apps.
- Various proprietary archives - .bar is used by several other games and applications as a generic archive extension.
Programs that open BAR files
Windows5 apps
Age of Empires 3
Paid Game reads .bar files automatically from its data directory; no user action needed. 
Resource Manager (Age of Myth Retold)
Free Community tool for extracting Retold .bar files; download from AoE forums. Technical details
deep spec| Format type | Proprietary binary game data archive |
| Encoding | Binary, little-endian |
| Compression | zlib per entry; some entries stored uncompressed |
| Archive structure | Header with file count + directory table; each entry has filename, offset, compressed size, uncompressed size |
| Typical archive size | 10 MB - 2 GB |
| Contents | Textures, 3D models, sounds, music, maps, UI elements, XML proto data |
| Format variants | Age of Mythology variant (2002); Age of Empires III variant (2005); Age of Mythology: Retold variant (2024) |
| Runtime access | Archives read directly by the game engine at runtime - not extracted to disk |
| Games using the format | Age of Mythology (2002), Age of Empires III (2005), Age of Mythology: Retold (2024) |
| Modding support | BAR Explorer, AoMED, and Resource Manager for Retold can extract archive contents |
| Documentation status | Undocumented by Microsoft; format understood through community reverse engineering |
| Released | 2002 (Age of Mythology) |
| Latest version | Used in Age of Mythology: Retold (2024) |
BAR conversions
Community Q&A
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