Skip to content
SplitMP3 home

Split M4A Files Online

Cut an M4A voice memo, podcast or audiobook into smaller M4A files in your browser.

Drop your audio file here

or choose one from your device

  • MP3
  • WAV
  • M4A
  • AAC
  • FLAC
  • OGG
  • OPUS
  • WEBM

Up to 100 MB. Your audio stays on your device.

You place the cuts while you listen

No file at hand?

How do you want to split? You can also decide after the file is open.

Play the file and add a cut wherever you want one, on the waveform. Choose your file above to start.

How do I split an M4A file?

Open your M4A file on this page, mark where each part should start, and press Download. SplitMP3 copies the AAC audio between your cuts into new M4A files and saves them as one ZIP.

  1. Choose your M4A or M4B file. It opens in your browser and is not uploaded.
  2. Click the waveform to place cuts, paste timestamps, or pick equal parts or a fixed length.
  3. Check the list of parts, rename them if you like, then download them one by one or as a ZIP.

Which M4A files can I split?

M4A is an MP4 file that holds only audio, almost always AAC. That covers iPhone Voice Memos, podcast downloads, songs you bought without copy protection, and audiobooks (.m4b, which keep their extension).

  • Voice memos. Save the recording to the Files app, then choose it here. Cut out the quiet start, or split a long meeting into topics.
  • Audiobooks. The chapter markers inside an M4B are not read. Type the chapter start times into the Timestamps tab and you get one file per chapter.
  • Not supported: ALAC files (Apple's own codec), copy-protected files (.m4p) and M4A files that contain something other than AAC. If a file has a video track, only its audio is kept.

The limit is file size: 100 MB on desktop browsers and 50 MB on phones and tablets. Many audiobooks are larger than that.

What happens to the sound and the tags?

The AAC data is not decoded or re-encoded. SplitMP3 copies the encoded packets between your cuts into a new M4A file, so the sound is not recompressed.

  • Cuts snap to the nearest AAC packet. A packet normally holds 1,024 samples, which is about 23 milliseconds at 44.1 kHz.
  • Title, artist, cover art and chapter markers are not copied into the parts. Rename the parts here, or use a tag editor afterwards.
  • The file is read by your browser through the File API; SplitMP3 has no server that receives audio.

Frequently asked questions

Can I split an iPhone Voice Memos recording?

Yes. Voice Memos are saved as M4A files. Share the memo to the Files app, then choose it from the file picker on this page. The parts are saved as M4A files on your phone.

Can I split an M4B audiobook by chapter?

Yes, if you have the chapter start times. SplitMP3 does not read the chapter markers inside the file, so type them into the Timestamps tab, one per line with the chapter title. Each chapter becomes its own M4B file.

Why does SplitMP3 say my M4A file is not supported?

The file probably holds ALAC audio (Apple's own codec) or is copy-protected. SplitMP3 splits AAC audio only. A file bought with copy protection cannot be opened by any browser tool.

Is the sound recompressed when I split an M4A file?

No. The AAC packets are copied into the new files exactly as they are stored. Because AAC is built from packets of about 23 milliseconds, a cut can only fall between two packets.

Will the parts play on my iPhone and in iTunes?

Each part is a complete M4A file with its own header, so players treat it like any other M4A. Cover art and track information from the original are not carried over.

Other ways to split

Last updated