Convert AVI to ALAC — Free Online Tool
Convert AVI video files to ALAC (Apple Lossless Audio Codec) M4A audio, extracting and losslessly compressing the audio track from the legacy Microsoft container into an Apple-native format. ALAC preserves every bit of the original audio data while delivering excellent compatibility with iTunes, Apple Music, and the entire Apple ecosystem.
to
FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
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Settings
Note: Browser-based encoding uses approximate quality targets. For precise CRF compression, copy the FFmpeg command above and run it on your desktop.
Estimated output:
Conversion Complete!
DownloadHow It Works
This conversion strips the video stream entirely from the AVI container and re-encodes only the audio track using Apple Lossless Audio Codec (ALAC), storing it in an MPEG-4 (.m4a) container. The audio from AVI files is commonly stored as MP3 (via libmp3lame) or AAC — ALAC is a lossless codec, so if the source audio is already lossy (MP3, AAC), the output will be losslessly compressed but cannot recover quality lost in the original encoding; no generation of new artifacts is introduced. The AVI container's interleaved audio-video structure is fully parsed, the audio packets are decoded, and then re-encoded to ALAC's lossless integer-based compression format. The resulting M4A file will be audio-only and will support metadata tags and chapters as defined by the MPEG-4 container spec.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg tool — in this browser-based tool, this runs via FFmpeg.wasm compiled to WebAssembly, processing your AVI file entirely locally without any server upload. |
-i input.avi
|
Specifies the input AVI file. FFmpeg parses the RIFF-based AVI container, identifying the interleaved audio and video streams within it for processing. |
-c:a alac
|
Sets the audio codec to Apple Lossless Audio Codec (ALAC), which decodes the AVI's audio stream to PCM and re-encodes it with integer-based lossless compression — preserving every bit of audio data with no quality loss beyond what already existed in the source. |
-c:a alac
|
This flag appears twice in the resolved command, which is redundant but harmless — FFmpeg simply applies the last valid instance. The effective instruction remains: encode the audio output as ALAC. No video codec flag is specified, so the video stream from the AVI is automatically dropped since the M4A container does not accept video in this configuration. |
output.m4a
|
Defines the output filename with the .m4a extension, which tells FFmpeg to wrap the ALAC-encoded audio in an MPEG-4 container — the standard Apple lossless audio delivery format compatible with iTunes, Apple Music, and all Apple devices. |
Common Use Cases
- Extracting a music performance or concert recording captured in AVI format to add to an iTunes or Apple Music library with full lossless quality preservation
- Archiving the audio from legacy AVI home video recordings into a modern lossless format for long-term preservation without any quality degradation
- Pulling clean audio from AVI screen recordings or tutorial videos to use as podcast source material in an Apple-centric post-production workflow
- Converting an AVI audio commentary track to ALAC so it can be imported into Logic Pro or GarageBand for further editing
- Extracting dialogue or voice-over audio from an AVI production file into a lossless ALAC M4A for use in an iOS or macOS app project
- Migrating a large collection of old AVI video files to audio-only ALAC archives to save storage while retaining every detail of the original audio fidelity
Frequently Asked Questions
Not in the purest sense. ALAC itself is a lossless codec, meaning it introduces zero additional quality loss during the conversion. However, if the original AVI file's audio track was already encoded with a lossy codec like MP3 or AAC, those compression artifacts are baked into the source data and cannot be undone. What ALAC guarantees is that after this conversion, the M4A file will be a bit-perfect, lossless copy of whatever audio was in the AVI — no new degradation is added.
If the AVI contained highly compressed lossy audio (e.g., 128k MP3), ALAC will losslessly store those decoded PCM samples, which can result in a larger audio file than the original lossy stream. ALAC achieves compression ratios roughly equivalent to FLAC (around 40–60% of raw PCM), but it will almost always be larger than lossy formats like MP3 or AAC at typical bitrates. The trade-off is the guarantee of zero quality loss.
ALAC has been open-sourced by Apple since 2011, so support has expanded significantly beyond Apple devices. VLC, foobar2000, and most modern media players support ALAC M4A files on Windows, Linux, and Android. However, ALAC is still primarily optimized for the Apple ecosystem — iTunes, Apple Music, iPhone, iPad, Mac, and Apple TV all support it natively. For broader cross-platform compatibility, formats like FLAC are often a better choice.
The video stream is discarded entirely. This tool is configured to output a pure audio M4A file using ALAC, so only the audio track from the AVI is processed. The MPEG-4 container used for M4A does not carry video in this output configuration. If you need to retain the video, you would need a different conversion target.
The displayed command handles a single file, but you can batch process on Linux or macOS with a shell loop: `for f in *.avi; do ffmpeg -i "$f" -c:a alac "${f%.avi}.m4a"; done`. On Windows Command Prompt, use: `for %f in (*.avi) do ffmpeg -i "%f" -c:a alac "%~nf.m4a"`. Each AVI file will produce a corresponding M4A file with the same base name. Since ALAC is a fixed-quality lossless codec, no quality parameter is needed.
AVI has limited and inconsistently implemented metadata support compared to modern containers. FFmpeg will attempt to map any available AVI metadata (such as title or artist stored in INFO chunks) to MPEG-4 M4A tags, but the results depend on how well-tagged the source AVI is. The MPEG-4 container used by ALAC M4A has robust support for iTunes-style metadata tags, so you can easily add or edit tags after conversion using tools like MP3Tag, iTunes, or MusicBrainz Picard.
Technical Notes
AVI (Audio Video Interleave) is a legacy Microsoft container from 1992 that stores audio and video in an interleaved RIFF-based structure. Its audio streams are most commonly encoded as PCM, MP3, or AC-3. When extracting to ALAC, FFmpeg decodes the audio stream to raw PCM and then re-encodes it using Apple's integer-based lossless compression algorithm, stored in an MPEG-4 (.m4a) container. ALAC does not support a variable bitrate quality parameter the way lossy codecs do — it operates at a single quality level: bit-perfect losslessness. One key limitation is that AVI does not support multiple audio tracks in the same reliable way as modern containers like MKV or MP4, so if the source AVI contains multiple audio streams, only the first (default) stream will typically be extracted. AVI files also do not carry chapter information, so no chapter data will be present in the output despite M4A's chapter support. The M4A MPEG-4 container is the standard Apple lossless delivery format and is fully compatible with iOS, macOS, tvOS, and watchOS without any additional codec installation.