Is this MP4 to M4A converter really free?

Yes. Up to 5 files at a time, no signup, no catch. The free tier adds a small watermark to image output — Pro ($9.99/mo or $49/yr) removes it, raises the file size limit to 500 MB, and unlocks unlimited batch conversion.

Are my files uploaded to a server?

No — and you can verify it yourself. Open DevTools → Network tab, then convert a file. You'll see zero upload requests. Everything runs right in your browser. We never see your files.

How long does conversion take?

Usually 1–3 seconds for a typical file. The very first conversion on a fresh page load may take 5–20 seconds while the converter engine loads — after that it's instant. Your CPU does all the work locally.

What is the file size limit?

Free: up to 10 MB per file, 5 files per batch. Pro: up to 500 MB per file, unlimited batch. If you're working with large videos or RAW photos, Pro is built for that.

Can I batch convert multiple MP4 files at once?

Yes — drop multiple files at once (or Ctrl/Cmd+click to select them) and they all convert in parallel. Free accounts handle up to 5 files per batch; Pro has no limit.

What bitrate will the converted audio use?

We default to 192 kbps for MP3, 128 kbps for OGG/Opus, and 320 kbps for M4A/AAC. These settings are perceptually transparent — most listeners can't tell the difference in a blind test.

Will my metadata (ID3 tags, album art) be preserved?

Yes, when both formats support it. Tags carry over on conversions like MP3→M4A or FLAC→MP3. WAV has limited tag support, so some metadata may not transfer.

Is converting MP4 to M4A lossless?

Yes — M4A is simply an MP4 container with only the audio track retained. No re-encoding occurs; the AAC audio data inside the MP4 is remuxed directly into the M4A file.

How do I add the M4A to iTunes or Apple Music?

Drag the M4A file into iTunes or Apple Music, or use File → Import. It will appear in your library immediately and can be synced to iPhone or iPad.

How private is this converter?

Completely private — by design, not policy. There is no upload endpoint. Files are processed right inside your browser tab and disappear the moment you close it. We collect only anonymous page-view counts; your file content is never seen or stored.

MP4 to M4A Converter — Free, Online, No Upload

How to convert MP4 to M4A online

1
Drop your MP4 file
Drag and drop your MPEG-4 Part 14 file onto the converter, or click to browse your files. You can select up to 5 at once. Nothing leaves your device — conversion happens right here in the browser.
2
Hit Convert — it happens locally
Click Convert and watch it go. There's no upload, no server queue, no waiting. The converter runs MPEG-4 Part 14 → MPEG-4 Audio entirely in your browser tab. Most files finish in 1–3 seconds.
3
Download your M4A
Your MPEG-4 Audio file is ready. Click Download, or grab a ZIP if you converted a batch. Close the tab and everything disappears — no copies kept anywhere.

MP4 vs M4A: format overview

MP4

MPEG-4 Part 14

Moving Picture Experts Group · 2001

Compression: lossy
Transparency: No

✓ Universal compatibility across all platforms
✓ Excellent compression with H.264/H.265
✗ H.264 has royalty implications

M4A

MPEG-4 Audio

Apple / MPEG Group · 2001

Compression: lossy
Transparency: No

✓ Better quality than MP3 at same bitrate (AAC codec)
✓ Native Apple ecosystem support

MP4 magic bytes: 00 00 00 xx 66 74 79 70

M4A magic bytes: 00 00 00 xx 66 74 79 70 4D 34 41

Why convert MP4 to M4A?

Someone sent you a video of a live performance, a spoken word recording, or a music session as an MP4. You want to add just the audio to your Apple Music library, sync it to your iPhone, or import it into GarageBand — but iTunes and Apple Music don't recognize raw MP4 files as audio. The solution is M4A: Apple's audio-only container, which is structurally identical to MP4 but carries only the audio track.

Converting MP4 to M4A is essentially a container rename. The AAC audio stream already inside your MP4 is remuxed directly into the M4A file without any re-encoding — which means the operation is near-instant and completely lossless. No quality is lost, no compression artifacts are added. Apple Music, iTunes, GarageBand, Logic Pro, and every iOS and macOS app that handles audio accept M4A without any fuss.

The M4A file will be significantly smaller than the original MP4 because the video track is discarded entirely. A 200 MB MP4 with 192 kbps AAC audio will produce an M4A of around 60–80 MB depending on duration. Drag it into Apple Music and it syncs to your iPhone on the next backup, or AirDrop it directly to any Apple device.

Quality & file size: MP4 to M4A

Typical file sizes: MP4 100–300 MB → M4A 3–6 MB.

Both MP4 and M4A use lossy compression. We transcode at high quality settings (equivalent to M4A's recommended web quality) to minimize generational loss.

Color depth: MP4 supports standard color, M4A supports standard color.

Transparency: MP4 does not support transparency. M4A does not support transparency — transparent areas become solid white.

Frequently asked questions

Privacy: how FormatDrop handles your files

Your MP4files are converted 100% inside your browser. They are never uploaded to our servers, never stored, and never seen by anyone other than you. This isn't a privacy policy claim — it's an architectural guarantee: our server has no endpoint that receives file bytes.