M4A to MP3 converter for recordings that play everywhere
M4A is what iPhones, Zoom, WhatsApp and many recorders save, and it confuses older car stereos, some website uploaders and Windows tools. Your todo.is agent converts your M4A files to MP3, sorts out names and dates, and can join several short recordings into one track.
The prompt
- Convert the attached M4A files to MP3: [ATTACH THE M4A FILES]. Use [BITRATE]. [JOIN OR SEPARATE]. Name each file [NAMING] and add the recording date to the tags if it is in the file. [CLEAN UP]. Tell me the length of each MP3 and send them back in a ZIP.
What to change
- [ATTACH THE M4A FILES]: Attach .m4a files, such as iPhone Voice Memos, Zoom audio, WhatsApp audio you saved, or a recorder app.
- [BITRATE]: E.g. "128 kbps for voice" or "256 kbps for music".
- [JOIN OR SEPARATE]: E.g. "keep one MP3 per file" or "join them into one MP3 in date order with a 1-second gap".
- [NAMING]: E.g. "date and title, like 2026-10-03 Choir rehearsal" or "keep the original names".
- [CLEAN UP]: E.g. "reduce background hum", "remove long silences" or "no changes".
Example result
- M4A to MP3: choir rehearsal recordings
- 9 M4A files from an iPhone · AAC · 44.1 kHz
- Result: 1 MP3 · 47 min · 128 kbps · 44 MB
- Order (by recording date)
- • 0:00 Warm-up, 3 Oct 18:02
- • 4:10 Soprano part, bars 1 to 32
- • 11:45 Alto part, bars 1 to 32
- • 18:30 Tenor and bass part
- • 26:05 Full run, take 1
- • 31:40 Full run, take 2
- • …
- • 44:20 Director's notes
- Each section is also saved as a chapter marker, and the list above is in the MP3 comment tag, so you can jump to your part.
- What your agent did
- • Converted the AAC audio inside each M4A to MP3 with ffmpeg
- • Joined the 9 recordings with a 1-second gap so sections are easy to hear
- • Reduced the low hum from the hall heating with a gentle filter, leaving the voices untouched
- • Set all sections to the same loudness, since the phone was moved closer for some parts
- Why convert M4A at all?
- • Older car stereos, some MP3 players and some upload forms only accept MP3
- • Some Windows apps cannot open M4A without extra software
- • Note: M4A is usually a bit smaller at the same quality. If everything you use plays M4A, you can keep it
- Protected files
- M4A files bought from the iTunes Store long ago may be copy-protected (M4P). Those cannot be converted.
How to do it with todo.is
- Copy the prompt and choose bitrate, joining and naming.
- Attach the M4A files in todo.is, or forward recordings straight to your agent on WhatsApp or Telegram.
- Your agent converts them and sends one MP3 or a ZIP of MP3s.
- Ask for more: "split my part out as its own file" or "transcribe the director's notes".
Tips for a better result
- To send an iPhone Voice Memo, tap Share in the Voice Memos app and pick todo.is, WhatsApp or email.
- Joining many short recordings into one MP3 with chapters makes rehearsals and lectures easier to replay.
- Converting M4A to MP3 does not improve quality. Pick a bitrate close to the original or slightly higher.
- Need the words, not the audio? Ask for a transcript instead of, or as well as, the MP3.
M4A to MP3 converter: FAQ
- Does M4A to MP3 lose quality? Both are compressed, so converting adds a tiny loss. At 128 kbps for voice or 256 kbps for music it is not noticeable.
- Can I join several M4A files into one MP3? Yes. Say the order, such as by date, and your agent joins them with an optional short gap.
- Can it convert WhatsApp voice notes? Yes. Forward the voice notes to your agent and ask for MP3. They are usually Opus or M4A audio, and both convert.
- Why can I not convert some old iTunes songs? Old iTunes purchases may be copy-protected M4P files. Protected files cannot be converted.
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