What is the BANK file format?
A .bank file is an FMOD Audio Bank, the binary container used by FMOD Studio (Firelight Technologies) to deliver compiled game audio to runtime engines. FMOD is one of the most widely used audio middleware platforms in the games industry, powering titles such as *Darkest Dungeon*, *Hollow Knight*, and *Celeste*.
Each .bank file packages compressed audio samples alongside FMOD Studio event graph data: trigger logic, parameter automation, transitions, and blend containers. The internal container is FSB5 (FMOD Sample Bank version 5), introduced with FMOD Studio 1.0 in 2014 - an evolution of the standalone .fsb sample bank used in older FMOD Ex titles. Audio can be compressed as Vorbis, FADPCM, PCM, or MP3, with platform-native codecs available for PlayStation (AT9) and Xbox (XMA). FMOD Studio also supports optional AES-128 encryption for DRM-protected banks.
Banks are exported from FMOD Studio as platform-specific builds and loaded at runtime by the FMOD Engine. In Unity-based games they typically reside in StreamingAssets/audio/generated/. A project usually ships with multiple banks: Master.bank holds the event index, Master.strings.bank provides name mappings, and additional content banks split audio by game area or category.
Modders and audio researchers can extract samples from .bank files using vgmstream (available as a Foobar2000 plugin or standalone CLI). The .bank extension is shared with unrelated synthesizer patch formats, but in a game files context the FSB5 header signature (FSB5 at byte offset 0) reliably identifies the FMOD format.
Security & safety
RISK: LOWFMOD .bank files contain audio data - no executable code. No known security vulnerabilities. Download .bank files only from legitimate game modding sources. Some games encrypt banks; decryption tools that bypass DRM may violate the game's EULA.
Format details
in a nutshell- Synthesizer/sampler instrument bank (generic) - Many hardware and software synthesizers use .bank for patch/preset collections; format varies by manufacturer (Roland, Korg, etc.).
- FL Studio instrument bank - FL Studio uses .bank for channel-state and instrument preset exports; different binary format from FMOD.
Programs that open BANK files
Windows3 apps
FMOD Studio
Freemium Use FMOD Studio to open, edit, and build .bank files. Free for small studios; licensed for commercial use above revenue threshold.
vgmstream (Foobar2000 plugin or CLI)
Open-source Install vgmstream plugin for Foobar2000 or use the CLI tool to extract and play audio streams from FMOD .bank files.
Darkest Dungeon (game)
Paid The game reads its own .bank files automatically at runtime; users do not open them manually. 
macOS1 app
Linux2 apps
Technical details
deep spec| Internal container | FSB5 (FMOD Sample Bank version 5) |
| Byte order | Little-endian |
| Magic signature | FSB5 (4 ASCII bytes) at offset 0 |
| Supported audio codecs | Vorbis, FADPCM, PCM, MP3; AT9 (PlayStation), XMA (Xbox) |
| Sample rate range | 8 kHz - 192 kHz; typically 44.1 kHz or 48 kHz for game audio |
| Encryption | Optional AES-128 (configurable per bank in FMOD Studio) |
| Typical file size | 1 MB - 500 MB |
| Event data | Includes FMOD event graph (triggers, parameters, transitions) alongside raw audio |
| Predecessor format | FSB1-FSB4 (FMOD Ex, pre-2014) |
| Common game path | StreamingAssets/audio/generated/ in Unity + FMOD projects |
| Required companion files | Master.bank (event index) + Master.strings.bank (name table) |
| Platform targets | Windows, macOS, Linux, PlayStation, Xbox, Nintendo Switch, iOS, Android |
| Released | 2014 (FMOD Studio 1.0, Firelight Technologies) |
| Latest version | FMOD Studio 2.x (2020-2026) |
| Specification | www.fmod.com |
BANK conversions
Community Q&A
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