AST File

What are AST files and how to open them

Are you having problems opening an AST file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your AST files.

What is an AST file?

AST files have multiple uses, and Actionamics Sound Tool Module is one of them. Read more about the other uses further down the page.

Actionamics Sound Tool Module

The .ast files are module files used by the Actionamics Sound Tool. The Actionamics Sound Tool is a software created by Michael Kleps used in the Dyna Blaster games. Actionamics is also the name of the game development team in which Kleps is a member. The Actionamics Sound Tool created music for the said game in 1991. Dyna Blaster games are popularly known as the Bomberman franchise games in the US.

How to open AST files

Important: Different programs may use files with the AST file extension for different purposes, so unless you are sure which format your AST file is, you may need to try a few different programs.

While we have not verified the apps ourselves yet, our users have suggested ten different AST openers which you will find listed below.

Last updated: August 22, 2026

All known file formats using extension .AST

While Actionamics Sound Tool Module is a popular type of AST-file, we know of 5 different uses of the .AST file extension. Different software may use files with the same extension for different types of data.

All Sound Tracker Module

.ast files are audio modules created by the All Sound Tracker software. The All Sound Tracker is a music sequencer software, an application used to create music.

AST Audio Stream

AST Audio Stream files are sound data files used by Nintendo on the Wii and GameCube for streaming audio such as background music in games. They store uncompressed 16-bit signed PCM sound, typically stereo, and sometimes surround sound, for titles like Super Mario Galaxy and The Legend of Zelda: Twilight Princess.

Such files are created by Nintendo's game development pipelines and are packaged into game discs or data archives. Their purpose is to stream audio in real time from the game disc or memory rather than relying on pre-decoded or compressed audio playback. Programs for gameplay or extraction (such as tools used by modders) read these files, parse the headers, extract PCM blocks, and send the sound data to audio output after appropriate byte-order handling.

All sound samples in these files are stored in big-endian order. A header of fixed size begins with an identifier, followed by metadata fields such as channel count, sample rate, total sample count, loop points, and block sizing. After the header, the file contains one or more "BLCK" chunks. Each chunk has its own mini-header, then PCM16 blocks, one block per audio channel.

In technical terms this format starts with the ASCII signature "STRM" at offset 0, and each data chunk begins with the ASCII signature "BLCK" at offset 64.

Need for Speed: Underground Soundtrack

.ast files are soundtrack files used in the Need for Speed: Underground game. Need for Speed: Underground is a multi-platform racing game, the seventh title in the Need for Speed series. .ast files feature the game's soundtrack, a total of 26 songs were embedded throughout the game's various missions or as background music. EA Black Box developed the game, and Electronic Arts published it in 2003.

Wii Sound Data

Wii Sound Data files are used by Nintendo during the GameCube/Wii era to store in-game music and other audio assets, especially in titles like Super Mario Galaxy and The Legend of Zelda: Twilight Princess. They serve as containers that hold sound data - typically uncompressed 16-bit PCM audio - segmented into blocks for playback on Wii hardware. The format supports loop points, stereo or multichannel audio, and includes metadata such as sample rate and total sample count.

These files are created during the game build process by Nintendo's internal tools or sound middleware for Wii titles. Once built into a game, they are packaged and used by the game engine to stream audio during gameplay. For archivists or developers extracting these files from game data, they are most often converted to common formats (such as WAV) for editing or listening using tools like vgmstream, which interpret the container, extract the PCM data, and respect loop and channel information.

Files begin with the ASCII signature STRM at offset 0, followed by a header including fields for audio format (ADPCM or PCM16), bit depth, channel count, sample rate, total samples, and loop start and end. After the 64-byte header, the file comprises one or more BLCK chunks, each starting with the ASCII "BLCK", a block size, padding, and the raw sound data.

Various apps that use files with this extension

These apps are known to open certain types of AST files. Remember, different programs may use AST files for different purposes, so you may need to try out a few of them to be able to open your specific file.

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