What is the BNK file format?
.bnk is most widely used as a Wwise SoundBank - a compiled audio package produced by Audiokinetic's Wwise audio middleware. A single .bnk SoundBank holds many individual files that store data used by the game, including audio tracks, sound effects, and event metadata. .bnk files are loaded by the game during gameplay.
Because .bnk files store many separate files, they can be seen as similar to ZIP archive files. Just as a ZIP file, .bnk file contents can be viewed and extracted using dedicated software such as wwiser or Wwise-Unpacker. Contents of a .bnk file can be modified after unpacking it, and any changes made to such a file will be reflected during gameplay.
Wwise SoundBanks are identified by the BKHD (Bank Header) magic bytes at file offset 0. Audio streams embedded in the bank are stored as .wem files and can be played back with tools such as vgmstream.
The .bnk extension is also used by unrelated formats - including Test Drive Unlimited game archives and AdLib instrument banks - which have different internal structures and magic bytes.
Security & safety
RISK: LOWSoundBanks themselves are passive data shipped inside games and carry little inherent risk. The real caution is around the tools: download extraction utilities only from their official GitHub repos, and avoid generic "BNK converter" or "BNK opener" websites that bundle adware/PUPs. Ripping game audio may also breach a game's EULA - fine for personal use, risky for redistribution.
Format details
in a nutshell- AdLib / Sound Blaster Instrument Bank - Legacy DOS-era FM-synth instrument bank (the original db_name); obsolete, opened by old SB/AdLib tools.
- Test Drive Unlimited game archive (Eden Games) - Proprietary container holding 3D car models, textures and sounds for TDU/TDU2; edited with TDU Modding Tools.
- ExamView Test Bank - Question bank for the ExamView assessment suite used by teachers; opens only in ExamView.
Programs that open BNK files
Windows5 apps
wwiser
Open-source Open the .bnk (keep companion .xml/.txt for names), generate TXTP, then play with vgmstream.
Wwise-Unpacker
Open-source Drop the .bnk in; it extracts the .wem files and converts them to OGG/WAV.
vgmstream (foobar2000 plugin / CLI)
Open-source Plays .wem extracted from the bank, or .txtp generated by wwiser, directly.
Audiokinetic Wwise
Freemium Official authoring tool - generates and inspects SoundBanks (for developers/modders). 
Linux1 app
Technical details
deep spec| Format type | Binary compiled audio container (SoundBank) |
| Magic bytes | BKHD (hex 42 4B 48 44) at file offset 0 |
| Developer | Audiokinetic (now part of Epic Games) |
| Chunk structure | IFF-like named chunks: BKHD, DIDX, DATA, HIRC, STID, PLAT |
| Supported audio codecs | PCM, Vorbis, ADPCM, Wwise Opus - codec selected per audio object |
| Companion format | .wem (Wwise Encoded Media) for individual audio streams |
| MIME type | application/octet-stream |
| Byte order | Little-endian on PC and current consoles; big-endian on legacy platforms (PS3, Wii) |
| Event and logic storage | HIRC chunk encodes audio events, states, switches, and RTPCs alongside audio data |
| External reference model | Audio may be embedded in the bank or reference external .wem files packaged in .pck archives |
| Platform support | PC, PlayStation, Xbox, Nintendo Switch, iOS, Android, and more |
| Extension collision | Same extension also used by TDU game archives, AdLib instrument banks, and ExamView test banks - distinct magic bytes |
| Version field | BKHD header stores the Wwise SDK version used to compile the bank |
| Bank types | Init bank (Init.bnk) loaded at startup; additional banks loaded per level, scene, or language |
| Extraction tools | wwiser, Wwise-Unpacker, BnkExtract, vgmstream |
| Released | 2006 (Wwise audio middleware) |
| Specification | www.audiokinetic.com |
BNK conversions
Community Q&A
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