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FFmpeg Audio Converters

Convert WMA, AC3, AMR, CAF, MP2, and MKV audio files to WAV, MP3, OGG, or AAC. Powered by FFmpeg running in WebAssembly. All conversion happens in your browser with no uploads.

5 min read
Updated 2026-04-13
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Certain audio formats require a full codec library to decode, including WMA from Windows Media Player, AC3 (Dolby Digital) from DVDs and broadcast, AMR voice recordings from Android devices, CAF from iOS and macOS apps, MP2 from broadcast television and radio, and audio tracks embedded in MKV video containers.

The Web Audio API built into browsers cannot decode these formats natively. This collection handles them by running FFmpeg entirely in your browser via WebAssembly. The WASM binary is loaded on demand from a CDN the first time you use a tool in this collection; subsequent conversions within the same session are immediate.

All conversion happens locally on your device. Your files are never uploaded to any server. The output formats (WAV, MP3, OGG, and AAC) cover the full range of use cases: WAV for editing in a DAW, MP3 for universal distribution, OGG for web and open-source platforms, and AAC for Apple devices and streaming services.

How to Use These Tools

Step-by-step guidance and best practices for getting the most out of this collection

The formats in this collection require a codec library to decode because they use compression algorithms not built into browser audio APIs.

WMA (Windows Media Audio) was developed by Microsoft and is the default output format of Windows Media Player and Windows voice recorder. While largely superseded by MP3 and AAC, WMA files are still common in older Windows media libraries and some recording devices.

AC3, also known as Dolby Digital, is the primary audio codec for DVDs and was widely used in early Blu-ray releases and North American broadcast television. It supports multichannel audio up to 5.1 and is still found in broadcast recordings, video game audio, and ripped DVD content.

AMR (Adaptive Multi-Rate) is a speech codec optimized for low-bitrate voice transmission. It is the standard recording format for voice memos and call recordings on Android devices running older versions of Android. AMR-NB (Narrowband) operates at 4.75–12.2 kbps; AMR-WB (Wideband) provides higher quality for voice calls.

CAF (Core Audio Format) is Apple's flexible audio container used in iOS and macOS applications. Unlike MP3 or AAC, CAF is not a codec but a container that can hold any audio codec Apple supports, including PCM, AAC, ALAC, MP3, and more. CAF files from iOS voice memos and GarageBand are typically encoded as AAC or PCM inside the CAF container.

MP2 (MPEG-1 Audio Layer II) is the predecessor to MP3 and remains the standard audio codec for digital broadcast television (DVB) in Europe and professional broadcast radio in many regions. MP2 is rarely used for consumer audio distribution, which means modern media players often lack support for it.

MKV (Matroska Video) is a flexible multimedia container that can hold video, audio, and subtitle tracks. The audio track in an MKV file may be encoded in any codec, commonly AAC, AC3, MP3, or DTS. Converting the audio track extracts it and re-encodes it to your chosen format, discarding the video.

WMA Converters

Convert Windows Media Audio files to standard formats

AC3 Converters

Convert Dolby Digital AC3 audio from DVDs and broadcast sources

AMR Converters

Convert Android voice memos and call recordings from AMR format

CAF Converters

Convert Apple Core Audio Format files from iOS and macOS

MP2 Converters

Convert MPEG-1 Audio Layer II files from broadcast and television sources

MKV Audio Extractors

Extract and convert the audio track from Matroska MKV video files

Popular Workflows

Common ways professionals use these tools together

Open WMA Files on Non-Windows Devices

  1. 1

    Upload your WMA file

    WMA to MP3 Converter

  2. 2

    Download the MP3, playable on any device or platform

    WMA to MP3 Converter

Extract Audio from an MKV Movie File

  1. 1

    Upload the MKV file to extract its audio track

    MKV to WAV Converter

  2. 2

    Edit or process the extracted WAV in an audio editor

    Audio Trimmer / Audio Normalizer

  3. 3

    Export the final audio to your target format

    WAV to MP3 / WAV to AAC

Convert Android Voice Memos for Transcription

  1. 1

    Upload the AMR voice memo from your Android device

    AMR to WAV Converter

  2. 2

    Use the WAV file with transcription software or services

    External transcription tool

Frequently Asked Questions

Everything you need to know about ffmpeg audio converters

Why does the first conversion take longer?

The first conversion loads the FFmpeg WebAssembly binary from a CDN. This is approximately 30 MB and takes a few seconds depending on your connection. Subsequent conversions within the same session are immediate because the binary remains loaded in memory.

Are my files uploaded to a server?

No. FFmpeg runs entirely in your browser via WebAssembly. Your audio files are processed locally on your device and never sent to any server. Only the FFmpeg binary itself is fetched from a CDN on first load.

Which output formats are available?

Each converter outputs to WAV, MP3, OGG, or AAC. WAV is suitable for editing in a DAW. MP3 offers the widest device compatibility for distribution. OGG is preferred for web audio and open-source platforms. AAC is used by Apple devices and most streaming services.

Does converting WMA or AC3 to WAV improve audio quality?

No. Converting a lossy file to WAV does not restore discarded audio data. The WAV output will have the same perceptual quality as the source. The benefit of WAV is that it allows further editing and re-encoding without introducing additional compression artifacts.

Can I extract audio from MKV files with multiple audio tracks?

The converter extracts the first audio track from the MKV container. If the file contains multiple tracks, only the default track will be extracted. For files with multiple tracks you want to select from, a desktop tool such as FFmpeg or MKVToolNix provides more control.

What happens to the video when I convert an MKV file?

The video track is discarded. Only the audio track is decoded and converted to your chosen output format.

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