M4A to MP3, on your device.
M4A is what iPhones, Voice Memos and most meeting apps produce — and what some car stereo, website uploader or old application refuses to accept. Drop the file here and it becomes an MP3 without being uploaded anywhere: your browser decodes it and re-encodes it in this tab.
Add your files
Drag files here, or press the button. Any common audio works — and videos too: we take just the sound out of an MP4 or MOV. Your files stay on your device the whole time.
MP3 · M4A · WAV · FLAC · Ogg · Opus · MP4 · MOV — even old AMR and WMA files. You can also paste a file from the clipboard.
Pick the format you want
Not sure? MP3 is the safe answer — it plays on everything.
Advanced options — quality, mono/stereo, volume+
The defaults are good — you can skip this whole box.
Higher = better sound, bigger file.
Mono halves the size — fine for voice.
Your privacy — live proof, not a promise
- Files uploaded
- 0 bytes
- Processing
- Not started yet
- Your files
- Stay in this browser tab — gone when it closes
- Converter engine
- Not downloaded — only fetched if a format needs it
One download, and it isn’t your audio
Converting to MP3 or WAV needs no download at all. Less common formats use a built-in converter engine (32.5 MB) that comes from this site — not from some other company — downloads once, and is then saved in your browser. Your audio is never part of that download: the engine comes to your files, your files don’t go to it.
Don’t take our word for it: open your browser’s DevTools, watch the Network tab, then convert a file. You’ll see nothing carrying your audio — because this page has no upload feature at all. There is nowhere for your file to go.
Scope note, so this stays exact: the claim is about your files — they never leave this device. The site around it is not claim-free. It loads Vercel Analytics for aggregate page traffic, plus Google Analytics and Ads tags if you accept the consent prompt. Those measure page visits and store-link clicks. They never receive your audio, because nothing does. Full privacy policy.
Converted files are never stored by this page — they exist only in this tab until you download them.
Shrinking, not just converting?
If the point is a smaller file — an attachment cap, a full phone — the free audio compressor solves backwards from a target size and lets you A/B the quality before you commit.
Convert, then transcribe
Need the words, not the audio? The free audio to text tool transcribes the same files on your device — no conversion step needed for anything a browser can decode. Or capture something new with the free online voice recorder.
Why M4A files keep needing this
M4A (an MP4 container holding AAC audio) is technically the better format — newer, more efficient at the same bitrate. But MP3 had a fifteen-year head start, so ancient car head units, cheap voice recorder hardware, some CMS uploaders and a long tail of Windows software accept only MP3. Converting doesn't improve the audio; it buys compatibility with things that never learned AAC.
What the conversion costs
Both formats compress sound by throwing a little detail away, so converting between them loses a tiny bit more — for speech at normal quality settings you will not hear it. Pick a bitrate at or above the source's (most M4A voice recordings are 64–128 kbps) rather than below it, unless shrinking the file is the actual goal — in which case the compressor page does that job with its eyes open.
Every browser decodes M4A natively
This is the easy case for the fast path: the browser's own decoder unpacks the AAC, and the MP3 encoder runs in a Web Worker in this tab. No 32 MB engine download, works offline, and a typical voice memo converts in seconds.
How the conversion works
The same four steps whatever you drop in — none of them involve a server. The free online audio converter hub explains the whole pipeline, the format chooser and the comparison with upload-based converters.
Your browser opens the file itself
Drop a file in, and your browser reads it with the same built-in player it uses to play sound on any website. Videos work too — we take just the sound out of an MP4 or MOV and leave the picture alone. At this point nothing has left your device, and nothing will.
Your device does the converting
For MP3 and WAV, a small converter runs right here in this tab. For less common formats — Opus, Ogg, FLAC, M4A, or old files like AMR and WMA — a bigger converter engine (ffmpeg, ~32 MB) downloads once from this site and then also runs on your device. Either way, the work happens on your computer or phone, not on a server.
Trim and tidy before converting
You can cut silence off the start and end, make the sound louder, and choose the quality — all before the file is converted, so it is only converted once. Hidden info inside the file (like when and where it was recorded) is removed automatically, because a file you are about to share should not quietly carry that.
Download straight from this tab
The finished file is built in this tab and handed to you as a normal download — one at a time, or a whole batch bundled into a single ZIP. Close the tab and everything in it is gone. There is no account and no cloud copy, because there is no cloud.
M4A to MP3 — questions, answered
Does converting M4A to MP3 lose quality?+
A little, because both formats are lossy and the audio is re-encoded. For speech at 128 kbps or higher the difference is inaudible in practice. Avoid converting at a bitrate below the source's unless your goal is a smaller file.
Can I convert iPhone Voice Memos to MP3 here?+
Yes — Voice Memos exports are .m4a. Share the memo to Files (or AirDrop it to a Mac), then drop it on this page. It is decoded and re-encoded in your browser; the recording never leaves your device.
Is there a file size or length limit for M4A to MP3?+
No imposed limit. The ceiling is your device's memory, since the file is decoded in the tab — multi-hour recordings work on a laptop, and the page warns you before starting anything your device will find heavy.
Is this audio converter really free, with no limits?+
Yes. No account, no daily limit, no file-size tier and no watermark. Your own device does the converting, so an extra file costs us nothing — there is simply nothing for us to charge for or to cap.
Is my audio uploaded anywhere?+
No. The file is opened and converted inside your browser, on your device. This feature has no upload button behind the scenes — there is nowhere for your audio to go. Want proof? Open your browser's DevTools, watch the Network tab while you convert, and you'll see nothing carrying your audio.
What is the maximum file size?+
We don't set one. The real limit is your device's memory, because the whole file is handled in this tab. Files over 2 GB are refused, and if a file looks heavy for your device, the page warns you before starting. A laptop handles multi-hour recordings; a phone prefers shorter ones.
Does it work offline?+
Converting to MP3 or WAV works offline once the page is open. Other formats (Opus, Ogg, FLAC, M4A) need the bigger converter engine, which downloads once (~32 MB) from this site — after that it's saved in your browser, so those conversions work without re-downloading too.
Can I convert video files to audio?+
Yes. Drop in an MP4, MOV or WebM video and you get just the sound out of it — that's the whole 'MP4 to MP3' trick. The video itself is never uploaded or changed; only its audio is read.
Why is there no 'paste a link' option?+
Because this tool is for your files, from your device. A link box would turn it into a tool for downloading other people's audio from around the web, which is not what it's for — and every link would send someone's listening history through a converter. Local files only, on purpose.
What does 'remove hidden info' actually remove?+
Details stored invisibly inside the file: title, artist, album art, the exact time it was recorded, which app or phone recorded it, and sometimes even GPS location. It's removed by default because a file you're about to share shouldn't quietly tell people all that. Turn the option off and the details are kept instead.
Other conversions
Files worth converting start as recordings.
BlackBox records your day straight to compact, transcribed, searchable files on your phone — nothing to convert afterwards. Free on iPhone and Android.