Convert M4A to OGG (Vorbis) Online
Convert Apple M4A (AAC) files to OGG Vorbis, the free and open audio format. Free, in your browser.
.m4a · up to 100 MB
What you can do
M4A to OGG: bring your Apple music to the open ecosystem
Patent-free
OGG Vorbis is 100% patent-free. Play on Linux, Android, and game engines without restrictions.
100% private
Your iTunes library never leaves your device. Local conversion via WebAssembly.
Game engines
The preferred format for Godot Engine and Unity audio assets in open-source projects.
Android native
OGG Vorbis has been natively supported on Android since version 1.0 in 2008.
How it works
Three steps, no hassle
Upload your M4A file
Drag or select your .m4a file. Up to 200 MB. No signup required.
AAC→Vorbis transcoding
The AAC audio from the M4A container is decoded and re-encoded to OGG Vorbis in your browser via WebAssembly.
Download your OGG
Audio ready for Linux, Android, game engines, and any platform preferring patent-free formats.
FAQ
Got questions?
This conversion is lossy-to-lossy: both AAC and Vorbis are lossy codecs, and the process involves decoding AAC to PCM and re-encoding it to Vorbis, introducing a second generation of compression artifacts. In practice, with Vorbis quality q5 (equivalent to ~160 kbps) or higher from a 128 kbps M4A source, the perceptual difference is minimal for most listeners. However, if maximum fidelity is the goal, it is ideal to start from the original uncompressed source (WAV, AIFF, or FLAC) when available. For purchased iTunes collections where no uncompressed source exists, M4A→OGG is the pragmatic path to migrating to platforms that do not support AAC.
OGG Vorbis is a completely patent-free format, developed by Xiph.org since 1993 (the organization was founded then) with the first stable Vorbis version released in 2000. Unlike AAC (developed by the Fraunhofer IIS, AT&T Bell Labs, Sony, and Nokia consortium, with active patents through at least 2026), Vorbis can be implemented, distributed, and played on any platform without license fees. This makes it especially valuable for the Linux ecosystem (where distributing AAC-capable players has legal restrictions in some countries), open-source game engines (Godot, Defold), Android (which has included native Vorbis support since version 1.0 in 2008), and any project where freedom from patent restrictions is a priority.
OGG Vorbis compatibility is broad but not universal. Android has supported OGG Vorbis natively since Android 1.0 (2008). Most desktop music players (VLC, foobar2000, Winamp, Clementine) play OGG without issue. Firefox and Chrome play OGG in the HTML5 <audio> tag. However, iOS and macOS do not include native Vorbis support (Apple only implements its own AAC/M4A ecosystem), though VLC for iOS does play it. Low-end hardware players may not support OGG. For web use or Android apps, OGG is an excellent choice.
Partially. Text metadata (title, artist, album, year, genre) stored in the M4A container as iTunes tags (ilst atoms in MP4) are converted to VorbisComment tags in the OGG container. However, cover art embedded in M4A may not transfer in all converters: the specification for embedded artwork in OGG Vorbis (via the METADATA_BLOCK_PICTURE field, adopted later) is not as universally implemented as in MP3 ID3v2 or FLAC. If cover art is important, verify the result with your preferred player.
Yes, and this is one of the most common use cases for this conversion. Godot Engine uses OGG Vorbis as the primary audio format for background music and sound effects, as it is the patent-free format with the best quality-to-compression balance for game assets. Unity also natively supports OGG Vorbis (alongside WAV and AIFF). If you have iTunes music in M4A format and want to use it as a soundtrack in a Godot game, converting to OGG is the necessary step. Remember to verify the usage rights of the music before including it in a commercial project.
At low bitrates (64–128 kbps), AAC (especially AAC-LC developed by Fraunhofer, and HE-AAC) outperforms Vorbis in perceptual quality, according to blind listening studies conducted by Hydrogenaudio.org between 2002 and 2010. At medium and high bitrates (160–320 kbps), both codecs are perceptually transparent for most musical material and the practical difference is negligible. Opus (Vorbis's successor also from Xiph.org, RFC 6716, 2012) clearly outperforms AAC at all bitrates, but OGG Opus is a different format from OGG Vorbis. For a 256 kbps M4A music file, converting to Vorbis q6 (~192 kbps) will produce a very high perceptual quality result.
Convert M4A to OGG: migrate from Apple AAC to the patent-free Vorbis format
The M4A format is an audio container based on MPEG-4 Part 14 (MP4), developed by Apple as the standard wrapper for AAC (Advanced Audio Coding) audio in its iTunes and QuickTime ecosystem. The .m4a extension (distinct from .mp4, which Apple reserves for files containing video) was introduced with iTunes 4 in 2003, when Apple launched the iTunes Music Store and established M4A/AAC as the digital music distribution format for its platform. AAC was standardized by ISO/IEC as MPEG-2 Part 7 in 1997 and subsequently expanded in MPEG-4 Part 3 in 1999, developed jointly by Fraunhofer IIS, AT&T Bell Labs, Sony, and Nokia. The AAC-LC (Low Complexity) profile, the most widely used in iTunes M4A files, offers superior perceptual quality to MP3 at the same bitrate: at 128 kbps, AAC-LC is approximately equivalent in perceptual quality to MP3 at 192 kbps according to Fraunhofer studies and blind listening evaluations at Hydrogenaudio.org. OGG Vorbis, in turn, is the free and open-source audio codec developed by Xiph.org, with the first stable version (Vorbis I) released in July 2000. The Xiph.org project was founded in 1993 by Monty Montgomery and others, with the explicit goal of developing patent-free alternatives to proprietary multimedia formats.
Transcoding from M4A (AAC) to OGG Vorbis involves three technical stages: first, demuxing the MPEG-4 container to extract the AAC audio stream; second, decoding AAC to PCM using an AAC-LC decoder (the reference decoder is FDK-AAC, originally developed by Fraunhofer IIS and open-sourced by Android in 2012); and third, encoding Vorbis from the PCM using libvorbis (the Xiph.org reference implementation). The conversion necessarily introduces a second generation of loss, as AAC and Vorbis are both lossy codecs and do not share a compressed-domain representation that would allow direct transcoding. However, when the M4A source is of sufficient quality (256 kbps or 128 kbps iTunes, which uses a high-quality AAC encoder) and the target Vorbis is encoded at quality q5 (~160 kbps) or higher, the additional loss is imperceptible in casual listening. Text metadata (iTunes ilst tags→VorbisComment) is automatically mapped during conversion.
M4A to OGG conversion covers several highly relevant practical scenarios. The most common is migrating iTunes libraries to Linux environments: Linux distributions (Ubuntu, Fedora, Debian) do not include the proprietary AAC decoder by default due to patent restrictions in certain countries, while OGG Vorbis is natively supported by all Linux players without additional codecs. The second frequent scenario is indie game development: Godot Engine, the most popular free game engine among indie developers, uses OGG Vorbis as the preferred format for background music and long sound effects, given its fully free license and compression efficiency. A developer who has purchased background music for their game from iTunes in M4A format needs to convert it to OGG to use it in Godot without codec license conflicts. Convertir.ai performs all M4A→OGG transcoding in the browser via WebAssembly, without uploading audio files to any server, guaranteeing the privacy of the user's music library.