How to Convert Audio to MP3 (Voice Memos, WAV, M4A and More)

To convert audio to MP3, open an audio converter, add your file (a voice memo, WAV, M4A, FLAC or even a video), choose MP3 as the output, pick a bitrate such as 192 kbps, and download the new file. With the free WoowTools audio converter this happens inside your browser, so the recording is never uploaded.

Below are the steps for every device, a bitrate table so you know what quality and size to expect, and the common mistake that leaves you with a file that will not play.

Why convert audio to MP3?

MP3 plays on practically every phone, car stereo, laptop, website and app. Other formats are great for their own job but cause trouble when you share them:

• M4A (iPhone voice memos, Windows Sound Recorder, many Android recorders) is not accepted by some upload forms, older car stereos and Windows apps.
• WAV is uncompressed, so a 10 minute recording is about 100 MB, too big for most email and chat apps.
• FLAC is lossless and smaller than WAV, but many players and websites still do not open it.
• Video files (MP4, MOV, WebM) are much larger than you need when you only want the sound.

MP3 trades a little quality you will rarely hear for a small file that works everywhere.

How to convert audio to MP3 in your browser

This works the same on Windows, Mac, Chromebook, iPhone and Android.

1. Open the audio converter.
2. Drop in your files or tap to choose them. You can add up to 20 at once. MP3, WAV, M4A, AAC, OGG, Opus, FLAC, MP4, MOV, MKV and WebM files are accepted.
3. Choose MP3 as the output format.
4. Pick a bitrate: 128, 192, 256 or 320 kbps. 192 kbps is the default and suits most uses.
5. Click convert, then download each MP3 (or all of them).

The converter reads each file's length, codec and sample rate first, so you can see what you are working with. Surround sound is mixed down to stereo, since MP3 at these bitrates is a stereo format.

How to convert a voice memo to MP3

Voice memos are almost always M4A files. The trick is getting the file out of the recorder app first.

On iPhone

1. Open Voice Memos, tap the recording, then tap the three dots (More).
2. Tap Share, then Save to Files, and pick a folder.
3. In Safari, open the audio converter, tap to add a file, and choose the memo from Files.
4. Choose MP3, convert, and download. The MP3 lands in your Downloads folder in Files.

On Android

Most recorder apps save M4A or similar files in a Recordings or Voice Recorder folder. Use the app's Share or Save option to put the file somewhere you can reach, then add it to the converter from Chrome and download the MP3.

On Windows or Mac

Windows Sound Recorder saves M4A files in Documents, in the Sound Recordings folder. On a Mac, drag a memo out of the Voice Memos app onto the desktop to get an M4A copy. Then drop the file into the converter.

No recorder at all? You can record straight in the browser with the online voice recorder and convert the result.

Which MP3 bitrate should you choose?

Bitrate decides both quality and size. For speech, 128 kbps is plenty; for music you care about, use 256 or 320 kbps.

Bitrate	Size per minute (about)	Good for
128 kbps	0.96 MB	Voice memos, lectures, podcasts, interviews
192 kbps	1.44 MB	General use, a safe default for mixed speech and music
256 kbps	1.92 MB	Music you will listen to on good headphones
320 kbps	2.4 MB	The highest MP3 setting, for archiving music as MP3

The converter uses a constant bitrate, so these sizes are predictable: a 30 minute lecture at 128 kbps comes out at about 29 MB.

One rule matters more than the number: converting cannot add quality that was never there. A 96 kbps voice memo converted at 320 kbps is simply a bigger file that sounds the same.

Can you just rename a file to .mp3?

No. Changing "memo.m4a" to "memo.mp3" only changes the name, not the audio inside. The file still holds AAC audio, so some players refuse it, upload forms reject it, and car stereos skip it. A real conversion decodes the audio and encodes it again as MP3, which is what a converter does.

Is it safe to convert audio online?

It depends on where the conversion happens. Many online converters upload your file to their server, convert it there and keep it for a while, which is a real concern for voice memos, interviews, meetings and medical or legal recordings.

The WoowTools converter decodes and encodes the audio inside your browser tab with the browser's own media features, so the file is not sent anywhere and nothing is stored after you close the page. It also means speed depends on your device: a few minutes of audio converts in seconds on a recent phone or laptop, while an hour long WAV takes longer on an older machine.

Mistakes that ruin the result

• Converting MP3 to MP3 again at a higher bitrate. It adds size, never quality. Keep the original.
• Re-converting the same file many times. Every lossy encode loses a little detail. Convert once from the best source you have.
• Using MP3 for editing. If you will cut, mix or master the audio, convert to WAV or FLAC first and make the MP3 last. Our WAV vs MP3 guide explains when each one fits.
• Uploading private recordings to a website that keeps them. A browser based converter avoids this because the file stays on your device.

Other conversions you might need

For a single format pair, the dedicated pages open with the right output already chosen: WAV to MP3, M4A to MP3 and MP4 to MP3 for the sound of a video.

Convert your audio now

Add your voice memo or audio files, choose MP3 and a bitrate, and download in seconds. Open the free audio converter; it also saves to WAV, M4A, OGG and FLAC when MP3 is not what you need.

Frequently asked questions

How do I convert a voice memo to MP3 for free?

Save the memo to your Files app or computer (it is usually an M4A file), open a free browser based audio converter, add the file, choose MP3 and download. On WoowTools the conversion runs in your browser, so the memo is not uploaded.

What is the best bitrate for MP3?

For speech, 128 kbps is enough and keeps files small. For general use 192 kbps is a safe default, and for music you care about, choose 256 or 320 kbps. A higher bitrate than the source had will not improve the sound.

Does converting to MP3 lose quality?

MP3 is a lossy format, so a little detail is removed, but at 192 kbps and above most people cannot hear the difference. Convert from the best original you have, and only once.

Can I convert video to MP3?

Yes. Add an MP4, MOV, MKV or WebM file to the audio converter and choose MP3. Only the sound track is kept, so the result is much smaller than the video.

Can I convert several audio files to MP3 at once?

Yes. The WoowTools audio converter takes up to 20 files at a time, converts each with the same format and bitrate, and lets you download them one by one or together.