WAV to MP3, MP3 to WAV: how to pick a format without regrets
Recording, editing, sharing over WeChat — should it be WAV or MP3? A rundown of the common audio formats and how to convert between them locally in the browser.
Voice recorders export WAV, WeChat only loves MP3; your editor wants lossless, your phone thinks the file is too big — converting audio format is something you run into almost every day. Pick the wrong container and you either cannot play the file, or it doubles in size, or you compress it once more and the high end is gone.
Here is how the formats compare, and then how to run a conversion with TwoThink Convert Audio Format in the browser. Nothing is uploaded.
First: lossless or lossy?
| Format | Type | Good for |
|---|---|---|
| WAV | Lossless PCM | Editing, post-production, keeping the master |
| FLAC | Lossless compression | Archiving, at about half the size of WAV |
| MP3 | Lossy | WeChat, car stereos, pretty much every player |
| M4A / AAC | Lossy | Apple devices; usually smaller than MP3 at the same bitrate |
| OGG / OPUS | Lossy | The web, speech, open-source projects |
The rule of thumb: edit in WAV / FLAC, share as MP3 / M4A.
Converting an MP3 back to WAV only puts the same lossy data in a bigger shell — it cannot bring back detail that is already gone. If you really need lossless, record in WAV or FLAC from the start.
Converting in three steps
Step 1: get the audio file
A .wav or .m4a exported from a voice recorder, a phone memo app or a meeting tool — or an audio track you already extracted. If it is still inside a video, run Extract Audio first.
Step 2: open the converter
Go to Convert Audio Format and drop the file into the browser. The transcoding happens locally.
Step 3: choose the target format
- Sharing over WeChat or listening on the go: MP3 — 192 kbps is plenty, 128 kbps if you want it smaller.
- Into an editor or DAW: WAV.
- Apple devices, podcast publishing: M4A.
- Archiving to disk: FLAC.
Hit convert, listen to the result, then download it.
Tuning bitrate and sample rate
- Bitrate only matters for MP3 / M4A / AAC / OGG / OPUS. 128k is usually enough for speech; for music go with 192k or 320k.
- Sample rate stays at the source by default. CD material is 44.1 kHz, film and voice-over are often 48 kHz; for speech you can drop to 16 kHz and then convert to MP3, which makes a noticeable difference to the file size.
- Opus does not support 44.1 kHz, so the tool switches to 48 kHz automatically to avoid a failed conversion.
Common pitfalls
- A voice recorder WAV will not send: convert to MP3 first. One minute of stereo WAV is roughly 10MB, which is over the WeChat limit.
- No software on the computer for a meeting m4a: convert to MP3 or WAV, which are far more compatible.
- The phone cannot play FLAC: support is patchy on many Android phones, so convert to MP3 before listening on the move.
- You want to turn a video straight into an MP3: that is extracting a track, not changing a container. Use Extract Audio instead of dropping an MP4 here.
How it fits with the video tools
When the footage is still the point: Trim Video to keep a clip → Extract Audio to pull the track → only then Convert Audio Format if you need a different container. Working on the sound alone is far faster than transcoding the whole video.
My advice
For narration and interviews I record WAV or M4A by default; once the edit is final and it needs to go out, I render one 192k MP3 with Convert Audio Format. Keep the master, send the lossy copy — nobody is short-changed.
Try it → Open Convert Audio Format, drag in a WAV from a voice recorder, convert it to MP3, listen to ten seconds and check the size. That tells you whether switching formats is worth it for your own material.