M4A to Text Converter

M4A is an audio file stored in the MPEG-4 container. The audio inside is almost always AAC, which is compressed, and occasionally Apple Lossless, which is not. The extension tells you the wrapper. It does not tell you the quality, the length, or whether it will transcribe well. What matters for transcription is what the microphone captured in the first place.

It is the default recording format across Apple's ecosystem, which is why so many transcription requests involve it. Voice Memos on iPhone, iPad and Mac writes M4A. Zoom saves the audio-only track of a local recording as M4A. Many podcast, dictation and note-taking apps export to it. If you have a recording from an Apple device and you did not choose a format, you probably have an M4A.

Upload the file using the box at the top of this page. If the recording is on your iPhone, open Voice Memos, tap the memo, use the Share button and save it to Files, then upload it from there. On a Mac the memo can be dragged straight out of the Voice Memos app onto the desktop.

Set the language to Auto and the spoken language is detected for you. Pick a specific language if you know it and want to be certain. Turn on speaker detection when more than one person talks, so each line in the transcript is attributed to a speaker rather than run together as one block.

Processing runs on our servers. When it finishes, the transcript appears on the page with a word count. Copy it, download it as a TXT file, or export SRT subtitles with timestamps if the audio belongs to a video.

A common detour is converting the M4A to MP3 before transcribing it, usually because an older tool only accepted MP3. That step is unnecessary here and slightly harmful. The converter reads AAC audio directly. Re-encoding a compressed file into another compressed format throws away a little more detail each time, and speech recognition works best on the least-mangled version of the audio you have.

Upload the original M4A. If the file was already converted somewhere else, the transcript will still work, but go back to the source recording when you can.

Because AAC is compressed, M4A files are small for their length. Voice Memos records in a compressed setting by default, and a one-hour memo is typically a few tens of megabytes. If you switched the app to its lossless setting, the same hour is several times larger.

The upload limit is 500 MB. For a default-quality Voice Memo that is many hours of audio in a single file, so lecture-length and meeting-length recordings fit without splitting. The practical limit is more likely to be your patience waiting for a very long transcript than the file cap.

The format is not the deciding factor. The recording conditions are. Speech recognition degrades quickly with distance from the microphone, background noise, and people talking over each other. A phone lying flat in the middle of a large table picks up the room more than the speakers.

Two things help before you record: put the phone closer to whoever matters most, and choose a quiet spot. Two things help after: set the language correctly, and turn on speaker detection for any conversation with more than one voice. Heavy accents and technical vocabulary are handled reasonably, but a proper noun the model has never seen will sometimes come out phonetically, so skim the transcript for names before you rely on it.

A few files carry the .m4a extension but are not plain audio. The most common is M4P, the protected format of old iTunes Store purchases, which cannot be decoded outside Apple's players. Some files are video in disguise: an MP4 renamed to .m4a will not open as audio. And an interrupted recording, for instance a memo cut off by a call, can leave a file that reports a duration but contains nothing readable.

TXT is the right export when the goal is notes, quotes, or something to paste into a document. SRT is the right one when the audio came from a video and you want captions with timestamps. Speaker detection matters most for interviews, user research sessions and meetings, where who said something is as important as what was said.

If you record on an iPhone regularly, the TranscribeX app records and transcribes in one step and keeps the notes on the device, so there is no export and upload cycle. And if you were hoping the Apple Watch could do this for you, we looked at what Apple's new on-wrist features actually produce. They summarize. They do not transcribe.