When you clean up a voice recording, you meet the same three file types over and over: WAV, MP3 and M4A. Video adds MP4 and MOV to the mix. The format you start with, and the one you export, affect quality, file size and whether the file plays where you need it.
Here's a practical guide to choosing.
The three audio formats in one table
| WAV | MP3 | M4A (AAC) | |
|---|---|---|---|
| Compression | None (uncompressed) | Lossy | Lossy, more efficient than MP3 |
| File size | Large | Small | Small |
| Quality | Exact copy of the recording | Good at sensible bitrates | Good, slightly better than MP3 at the same bitrate |
| Plays everywhere | Nearly | Yes | Nearly; most phones, browsers and apps |
| Best for | Editing, masters, archives | Distribution, podcasts | Phone recordings, Apple devices, distribution |
Lossy means the encoder throws away detail it judges you won't hear, to make the file smaller. Done once at a sensible bitrate, it's hard to notice. Done repeatedly (open an MP3, edit, export MP3 again, repeat), it adds up.
What each is good at
WAV
WAV stores the audio exactly as recorded. Recorders, audio interfaces and editing software use it because nothing is lost.
- Use it for: the master of your project, files you'll keep editing, archives.
- Avoid it for: sending to listeners or uploading to slow connections; the files are large.
MP3
MP3 is the universal format. Every app and device plays it, which is why podcasts use it.
- Use it for: podcast episodes, sharing audio with anyone, anything where compatibility matters most.
- Avoid it for: intermediate files in an edit; each re-save loses a little more.
M4A (AAC)
M4A is usually AAC audio in an MP4-style container. Phones commonly use it for voice memos, and video files use AAC for their audio tracks.
- Use it for: distribution where your platform supports it, phone recordings, files headed to Apple devices.
- Avoid it for: very old players or services that only accept MP3.
And the video formats?
MP4 and MOV are containers: they hold a video track and an audio track (usually AAC). When you clean the audio of a video, the video track doesn't need to change at all. Our tool copies the picture as-is, without re-encoding, and replaces only the audio track, kept in sync. See MP4 noise removal for MP4 specifically; MOV, WebM and MKV work the same way.
Which format to clean
Always clean the best version you have. That means:
- The original file from the recorder, phone or camera, whatever its format.
- Not a copy downloaded from a social platform or sent through a messaging app.
- Not an MP3 you've already exported from an edit, if you still have the WAV.
Converting an MP3 to WAV before cleaning doesn't help: the detail the MP3 removed doesn't come back. Just clean the MP3. Our tool accepts WAV, MP3, M4A/AAC, OGG/Opus and FLAC audio, and MP4, MOV, WebM and MKV video.
Which format to export
Our tool returns the same format you gave it by default, or WAV, MP3 or M4A if you choose. A simple rule:
- Still editing? Export WAV. It's lossless, keeps the original sample rate and bit depth, and has exactly the same timing as the original, so it lines up on your timeline. See WAV noise removal.
- Publishing a podcast? Export MP3 (or M4A if your host supports it). MP3 comes back at the original bitrate. See MP3 noise removal and the best export settings for podcast audio.
- Sharing a voice memo or interview? M4A or MP3: small and widely playable.
- Cleaning a video? Keep the original format to get a video back with the clean audio, or choose an audio format if you only need the sound.
Sample rate and bit depth
Two more numbers appear next to formats:
- Sample rate is how many times per second the audio is measured. 44.1 kHz and 48 kHz are both fine for voice; video normally uses 48 kHz.
- Bit depth (for WAV) is how precisely each measurement is stored. 16-bit is fine for finished files; 24-bit gives more headroom while recording and editing.
You don't need to change either when you clean a file. A cleaned WAV comes back with the same sample rate and bit depth as the original, so it drops straight back into your project.
Common questions
Is WAV always better? As a working file, yes. As a file for listeners, no: a well-made MP3 or M4A sounds the same to most people and is far smaller.
Will cleaning an MP3 make it worse? Exporting to MP3 again means a second round of lossy compression, but at the original bitrate this is usually hard to hear. If you'll edit further, export WAV to avoid it.
What about FLAC? FLAC is lossless like WAV but smaller. It's a good archive format. You can clean FLAC files and export them as WAV for editing.
Mono or stereo? Stereo files keep two channels when you export WAV. For spoken-word podcasts, mono is often the better final choice; see the export settings guide.
A quick decision path
- Find the original file.
- Clean it in the tool.
- Export WAV if you're still editing; MP3 or M4A if you're publishing audio; the original format if it's a video.
- Keep the original and the WAV master.
If you're unsure what your noise is, hum, hiss and fan noise: causes and fixes helps identify it.