MP4 to M4A Converter

MP4 to M4A — What You're Actually Converting

M4A and MP4 are the same MPEG-4 container (ISO/IEC 14496-14) wearing two different file extensions: .mp4 carries video and audio together, while .m4a carries audio only. Converting MP4 to M4A strips away the video track and keeps the sound, and when the audio inside your MP4 is already AAC, that step can be a lossless stream copy — no re-encode, no quality drop. If you just want the audio out of a video for a playlist, iPhone, or podcast feed, this is the right conversion; if you need the file to play in a strict MP3-only device, convert to MP3 instead.

M4A vs MP4 — Side-by-side

When to Pick M4A

• You only need the audio — a song, interview, lecture, or podcast pulled out of a video clip.
• You live in the Apple ecosystem: M4A is the native format iTunes and Apple Music use for purchased tracks (256 kbps AAC, the old "iTunes Plus").
• The source MP4 already holds AAC audio and you want the smallest file with zero re-encode loss.
• You want better sound than MP3 at the same bitrate — AAC, the codec inside most M4A files, was designed as the MP3 successor and generally beats it byte-for-byte.

When to Stay on MP4

• You need the video, not just the soundtrack — keep the original MP4.
• You're targeting a device or app that only accepts MP3 (some car stereos, older players). Use MP4 to MP3 instead.
• You want the raw AAC stream with no container at all (some embedded hardware) — convert to a bare .aac file rather than an M4A.

How to Convert MP4 to M4A

1. Upload Your MP4 File: Drag and drop your .mp4 or .m4v file onto the page, or click "Add Files." Several files can be queued and converted with the same settings.
2. Set the Audio Codec: Open Advanced Options. Leave Audio Codec on AAC for the smallest Apple-friendly file, or switch to FLAC/ALAC if you want a lossless M4A.
3. Choose Quality Preset or Constant Bitrate: Use Quality Preset for a quick "Very High / High" choice, or pick a fixed value under Constant Bitrate — 256 kbps matches iTunes downloads, 128 kbps keeps files tiny. The Trim control can clip out just the part you need.
4. Convert and Download: Click "Convert" and save your M4A. No sign-up, no watermark.

Frequently Asked Questions

Is converting MP4 to M4A lossless?

It can be. If the audio track inside your MP4 is already AAC (it usually is) and you keep the AAC codec, the conversion is a stream copy — the audio is moved into the .m4a container untouched, with no re-encoding and no quality loss. If you change the codec or lower the bitrate, that step re-encodes and is lossy by definition.

Is M4A the same as MP4 audio?

Effectively yes. Both use the MPEG-4 / ISO Base Media File Format container, and an M4A file is just an MPEG-4 file that contains only an audio track. The .m4a extension exists so audio players and operating systems treat the file as music rather than video; the underlying bytes of the AAC audio are identical to what was in the MP4.

Will M4A play on Android and Windows, or only Apple devices?

M4A started as an Apple convention, but support is now broad. It plays in VLC, Windows Media Player, modern Android phones, and most browsers and media players. The narrow cases are some older or very basic devices that only read MP3 — for those, convert to MP3 instead.

Should I choose M4A (AAC) or MP3 for the audio?

For new files, AAC inside M4A is the better default: it was designed as the MP3 successor and generally sounds better at the same bitrate, and it's what Apple Music and iTunes use. Pick MP3 only when a target device or workflow specifically requires it — MP3's edge is universal compatibility, not quality.

What bitrate should I use for the M4A?

In our testing, a 3-minute stereo MP4 soundtrack exported to AAC at 256 kbps lands around 5.7 MB and is transparent for almost all listeners — this matches Apple's iTunes download quality. Drop to 128 kbps (roughly half the size) for speech, audiobooks, or podcasts where fidelity matters less; the ITU considers ~128 kbps AAC perceptually transparent for music already.

My M4A is too big to email — what are my options?

A long, high-bitrate M4A can exceed mail limits — Gmail, for example, caps attachments at 25 MB and swaps anything larger for a Google Drive link. Re-run the conversion at a lower Constant Bitrate (128 kbps roughly halves a 256 kbps file), use the Trim control to export only the segment you need, or run the result through Compress M4A to hit a specific target size.