ADX File

What are ADX files and how to open them

Are you having problems opening an ADX 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 ADX files.

What is an ADX file?

ADX files have multiple uses, and ADX lossy compressed audio is one of them. Read more about the other uses further down the page.

ADX lossy compressed audio

These ADX files contain the lossy proprietary audio compression format used for video games. CRI Middleware created this audio format. The looping function of ADX audio made this format useful for background sounds in video games. Sega Dreamcast made use of this audio format for their video games. The Sonic the Hedgehog series makes use of this audio format.

How to open ADX files

Important: Different programs may use files with the ADX file extension for different purposes, so unless you are sure which format your ADX 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 ADX openers which you will find listed below.

Last updated: August 17, 2026

All known file formats using extension .ADX

While ADX lossy compressed audio is a popular type of ADX-file, we know of 5 different uses of the .ADX file extension. Different software may use files with the same extension for different types of data.

Aodix project

These ADX files contain audio created by Aodix, a software designed by Juan Antonio Arguelles that acts as a basic sequencer program and uses the Amiga style "tracker" interface. It has an integrated sampler and synth and progressively drops in favor of a VST (Virtual Studio Technology) host. Due to the passing of the developer, Juan Antonio Arguelles, this software is unfinished. The last version released was Aodix v4 that came with its own set of new features.

Lotus Approach Database index

These ADX files contain the indexes of your database created in Lotus Approach, a database management system. You can do regular maintenance on your indexes to ensure it doesn't grow more extensive than what the database itself can support. Maintenance also helps to get rid of corrupt files that can potentially damage your database.

MSX Sound Performance System Player XPL-A Song

MSX Sound Performance System Player XPL-A songs are music data files created for the XPL-A (also written XPLA) music player system by composer-programmer Mstz80ax for MSX computers. They store complete song information including musical tracks, instrument settings, sample data (when used), and driver routines needed for playback on MSX hardware or emulation. These files are used wherever composed music needs to be played via the XPL-A player under MSX-DOS or inside a game or demo using that format.

An XPL-A song file is produced by composing music in the XEDT editor, then exporting or saving as an .adx data file which the XPL-A player or ADXP (Quick ADX Player) reads. Playback uses MSX sound chips such as YM2413 (OPLL), the Y8950 (MSX-AUDIO), PCM on MSX turboR, PSG, SCC+, and possibly multiple FM-PAC cartridges. Composers can include PCM sample data by referencing external sample files embedded or named within the .adx, enabling richer sound effects or sample-based voices alongside FM and PSG/OPL channels.

Files beginning with specific byte patterns ("bytes 0x012500 at offset 0 (ASCII: ".%")", followed by a zero byte at offset 4, then a long string of zeroes from offset 7) identify them unambiguously as XPL-A songs.

TunerPro Datastream Definition Format

TunerPro Datastream Definition Format is a text-based file type used by TunerPro RT software to define how live data (real-time vehicle or device outputs) is read, interpreted, and displayed. It establishes the rules for data acquisition, including which commands TunerPro sends/receives, how often, and how bytes from the stream map to meaningful units like temperature, RPM, or voltage.

These files are created by users (or vendors) familiar with the datastream from an ECU, OBD interface, wideband sensor, or similar device. Once the ADX is loaded into TunerPro RT, the program uses it to communicate properly - setting baud rate, packet size, offsets, scaling equations, units - and to display dashboards, value lists, or gauges from the incoming data.

ADX replaced the earlier ADS format starting with TunerPro V5; old ADS files can be imported and converted into ADX definitions to work with later versions of the software.

Files of this format often begin with an ASCII header string like .ADXFORMATversion= at the very start. They contain identifiable keywords and fields such as Packettoffset, SizeinBits, Units, MathEquation, RangeLow/High, EntryType, Baud, Title, and more, which together define how each parameter in the datastream should be parsed and transformed. These internal markers allow TunerPro to link raw bytes into usable telemetry.

Various apps that use files with this extension

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

Help us help others

File.org helps thousands of users every day, and we would love to hear from you if you have additional information about ADX file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.