What Is an AC3 File?

You can play AC3 files using most audio players

By
Tim Fisher
Photo of Tim Fisher, Lifewire GM and Writer
Tim Fisher
Senior Vice President & Group General Manager, Tech & Sustainability
  • Emporia State University

Tim Fisher has more than 30 years' of professional technology experience. He's been writing about tech for more than two decades and serves as the SVP and General Manager of Lifewire.

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Updated on September 9, 2022

What to Know

  • An AC3 file is an Audio Codec 3 file.
  • Open one with VLC or Windows Media Player.
  • Convert AC3 to MP3, WAV, AAC, etc., at Zamzar.

This article explains what an AC3 file is, how to open one, and how to convert one to a different audio file format.

What Is an AC3 File?

A file with the AC3 file extension is an Audio Codec 3 file. Much like the MP3 format, this one uses lossy compression to reduce the overall size of the file. It was created by Dolby Laboratories and is often the sound format used in movie theaters, video games, and DVDs.

AC3 audio files are designed to support surround sound. They have separate channels for each speaker in a surround sound setup. Five of the speakers are dedicated to a normal range and one speaker is dedicated to low-frequency subwoofer output. This corresponds to the configuration of 5:1 surround sound setups.

AC3 files that open with VLC in Windows 10

How to Play an AC3 File

AC3 files can be opened with VLC, QuickTime, Windows Media Player, MPlayer, and other multi-format media players, such as CyberLink PowerDVD.

If you find that an application on your PC tries to open the file, but it's the wrong application, or you'd rather have another installed program open it, you can designate a different default program for AC3 files in Windows. 

How to Convert an AC3 File

Several free audio converters support converting AC3 files to other audio formats such as MP3, AAC, WAV, M4A, and M4R.

Zamzar and FileZigZag work in your web browser to convert the file. Just upload it to one of the websites, choose an output format, and then save the converted file to your computer.

Still Can't Open It?

If you've tried opening it with the programs mentioned above, but it's still not working, re-read the file extension. It's easy to confuse another file for this one if their file extensions are similar, which is pretty common.

For example, A3D files might look related to this format, but those are actually Alternativa Player 3D export files that don't contain any audio data.

AC (Autoconf script) is another. Although it's missing just the number at the end, the format itself is completely unrelated and has nothing to do with AC3 files.

Some others you might misread as this one include AAC and ACO.

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