What Is a .adp File? .adp Format, MIME & How to Open

Quick facts

Extension.adp

File typeADP Audio

MIME typeaudio/adpcm

CategoryAudio

Charset—

Compressible—

What is .adp

What is a .adp file?

A .adp file is a ADP Audio. It is an audio format used to store music, voice and sound effects, either lossy or lossless.

In the mime-db registry it maps to audio/adpcm. When serving .adp over HTTP, set the Content-Type header as shown in Developer info below.

Related entities: it maps to audio/adpcm and is used by Tcl among others — and is delivered over HTTP via the Content-Type header.

How to open .adp files

Use VLC or Windows Media Player to open and edit .adp files.
Any text editor (Notepad, VS Code) can inspect the raw content as text.

Developer info

When served over HTTP, responses should set the following header:

Content-Type: audio/adpcm

Common software that reads/writes .adp:

VLCWindows Media PlayerAudacityQuickTime

Relation chain

.adpextension of

format

ADP Audioserved as

mime type

audio/adpcmsent via header

http header

Related extensions

Related MIME types

Related programming languages

Tcl

.tcl .adp .sdc

Common uses

Music and podcasts
Sound effects
Voice recordings

How to edit .adp files

Open the file with VLC, make your changes and save.
Most editors preserve the original formatting and encoding — avoid changing the charset.

How to create .adp files

Create a new file and save it with the .adp extension, or export this format from VLC.

Frequently asked questions

What programs can open .adp files?

Common options include VLC, Windows Media Player, Audacity. You can also open many of these files with built-in viewers or a browser.

How do I create a .adp file?

Create a new file in any text editor or the app that owns the format and save it with the .adp extension.

What is the relationship between .adp and the audio/adpcm MIME type?

audio/adpcm is the media type identifier used for .adp files during network transfer (for example in the HTTP Content-Type header).

Sources & standards

Updated 2026-08-18

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