Extract text from JA files
To convert your JA file to another format, you need Mozilla Firefox or other Compressed software.
To convert other file formats to the "Resource Archive" file type, you need software like Mozilla Firefox or a similar tool.
The .JA file extension typically refers to a Mozilla Archive (specifically omni.ja), used by Mozilla Firefox to store browser resources, scripts, and chrome data. While technically a ZIP container, Firefox optimizes the internal structure for faster startup times, meaning the operating system does not natively recognize it as an archive. This creates immediate friction for users trying to inspect browser code or recover data, as double-clicking the file triggers an "Unknown File Type" error. To access the contents - such as HTML, CSS, or JavaScript files - users typically need to rename the extension to ZIP or force-open it with a tool like 7-Zip.
A secondary but significant use case is the Jet Archive format found in Trainz Simulator games (developed by N3V Games). These proprietary archives pack thousands of game assets (textures, meshes, audio) to reduce load times. Unlike the Mozilla variant, Trainz .JA files are often encrypted or use a proprietary structure that standard ZIP tools cannot handle, often requiring specific modding utilities like GS (GameScript) tools or the Trainz Content Manager to extract assets. For audio files in games like Cyberpunk 2077, a .JA file may act as a container for Wwise audio banks, requiring specialized extraction to convert to listenable formats like MP3 or WAV.
Convert.Guru analyzes your JA file, detects the exact format, and lets you read the text inside.
Users also converted GEOPCDX, OVL, MPQ, US, EC and TT files.
If you want to convert JA file to US, EC, TT, CSV, JSON, XML, YAML, YML, TOML, INI, CFG or CONF, you can use Mozilla Firefox or similar software from the "Application Resource Archive" category. In the File menu, look for Save As… or Export….
To convert DBF, XML, SQLITE, XLSX, SQL, TSV, ACCDB, YAML, MDB, CSV, ODS or JSON files to JA, try Mozilla Firefox or another comparable tool in the "Application Resource Archive" category.
The history of Convert.Guru began over 25 years ago in California with Tom Simondi’s file-format database. A former contributor to Space Shuttle development and a software pioneer of the 1980s, Simondi established a trusted resource for file type analysis that was even referenced by Microsoft Windows XP. Today, we use modern technology to process and convert thousands of file formats while continually improving our JA converter.