Audio converter · Windows 10 and 11
Convert WAV to MP3
Uncompressed WAV runs to roughly 10 MB a minute at CD quality, too much for email, phones and most upload forms. Octoolo turns one recording or a whole folder of them into MP3s a quarter to a tenth the size, right on your own PC.
How to convert WAV to MP3
- 1
Go to Convert sound files
Open Converters from Octoolo's home screen and pick Convert audio. On first use Octoolo fetches FFmpeg (77 MB, checked against its fingerprint) and keeps it for next time.
- 2
Add the recordings
Drag in WAV files or the folder that holds them, or use Choose files. Each one is listed with its length, sample rate and size, so you know what you're about to shrink.
- 3
Pick MP3 and a quality
Click the MP3 tile. High means 320 kbps, Balanced 192, Small 128. A WAV has no bit rate of its own to keep, so As it is also gives 320 kbps.
- 4
Convert
Press Convert 8 files to MP3 (the button counts your files). At the end, a summary compares the total size before and after, and Show in folder opens the folder with the new MP3s.
WAV and MP3 compared
| Detail | WAV | MP3 |
|---|---|---|
| Full name | Waveform Audio File Format | MPEG-1 Audio Layer III |
| Compression | None: uncompressed PCM | Lossy: leaves out what the ear notices least |
| Size | About 10 MB a minute at CD quality (44.1 kHz, 16-bit, stereo) | About 1 MB a minute at 128 kbps, 2.4 MB at 320 kbps |
| Best for | Editing, mixing, samples, sound effects and burning CDs | Playing and sharing music anywhere |
| Plays in | Every audio editor and music app, Windows and Mac | Every phone, player, car stereo and browser |
| Since | 1991, Microsoft and IBM | 1993, Fraunhofer and MPEG |
Where the big WAV files come from
WAV is what most recording gear and music software writes by default, because it is simple and loses nothing. That is also why the files pile up so fast:
- Voice and interview recordings. Octoolo's own voice recorder saves mono 48 kHz WAV, and so do many handheld recorders.
- Mixes and bounces from a music app, often 24-bit at 48 kHz or more, which is 17 MB a minute and up.
- CD rips and sample libraries kept as WAV to be safe.
A ten-minute CD-quality WAV is about 106 MB, well over what most mail services will attach. As a 192 kbps MP3 it is about 14 MB: small enough to email, post to a podcast host or send in a chat, and it plays on every phone and car stereo. A two-hour meeting recorded in mono shrinks from about 690 MB to under 60 MB at Small.
Choosing a bit rate
| For | Quality | Bit rate | About a minute |
|---|---|---|---|
| Finished music, mixes you share | High | 320 kbps | 2.4 MB |
| Demos, everyday listening, podcasts with music | Balanced | 192 kbps | 1.4 MB |
| Talks, lectures, meetings | Small | 128 kbps | 1 MB |
Those rates are for stereo. A mono WAV, like most voice recordings, gets half of each preset (160, 96 or 64 kbps), because a single channel carries half as much. To set a rate yourself, open More settings and pick a Bit rate from 320 down to 64 kbps. Octoolo writes a constant bit rate, so the size is easy to predict: minutes times the figure above.
Hi-res WAVs are fine too. MP3 tops out at 48 kHz, so 88.2, 96 and 192 kHz recordings are written at 48 kHz, and 24-bit or 32-bit float samples are simply encoded: an MP3 has no bit depth of its own.
What you give up, and when to keep the WAV
MP3 is lossy: the encoder drops detail it expects you not to hear. At 320 or 192 kbps that is very hard to notice when you listen, but it matters if you plan to edit the sound again, because every new MP3 made from an MP3 drops a little more. Keep the WAV as your master and treat the MP3 as the copy you hand out.
Turning an MP3 back into WAV later will not bring the detail back (see MP3 to WAV). If you want smaller files without losing anything, WAV to FLAC roughly halves the size and keeps every bit, and WAV to M4A makes AAC files that suit iPhones.
Your WAVs are never changed. The MP3 is written as a separate file next to its WAV with the same name, and when that name is already taken the new one is called “Take 3 (2).mp3” instead.
Other ways on Windows
Audacity exports MP3 from whatever project is open, one at a time, and its Macros feature can process a folder once you have set one up. VLC converts through Media, Convert / Save, which suits a single file but gets slow for a batch.
Octoolo's converter is built for the batch case: drop a folder, pick a preset, and every WAV gets its MP3 beside it, four at a time, with nothing to set up first and the originals left untouched. If a recording needs trimming or a volume lift before it goes out, the Audio Editor in the same app does that; see MP3 cutter and normalize audio.
Octoolo or an online converter?
| Detail | Octoolo | A typical online tool |
|---|---|---|
| Your files | Stay on your computer | Usually uploaded to the site's server |
| Without internet | Works | Does not work |
| File size | No limit | Often capped on free use |
| Many files | Whole folders at once | Often a few at a time |
| Watermarks and ads | None | Common on free plans |
| Cost | $4.99 a month, all 17 apps | Free with limits, or a plan per site |
Questions, answered
How much smaller is the MP3?
Compared with CD-quality WAV (1,411 kbps), a 320 kbps MP3 is about 77% smaller, 192 kbps about 86% and 128 kbps about 91%. The summary after each batch shows the real figure for your files.
Will a mono voice recording become stereo?
No. Channels stay as recorded unless you pick Stereo or Mono under More settings, and the presets use half the stereo bit rate for a single channel, so the file stays lean.
Can I convert 24-bit or 96 kHz WAVs?
Yes. Octoolo reads them in full and writes the MP3 at 48 kHz, the highest rate the format allows. Keep the original if you will need that resolution later.
Where do the MP3s go?
Beside each WAV, unless you choose A folder I choose… under Save in. If a WAV sits somewhere Octoolo can't write, like a write-protected USB stick, that MP3 lands in Music\Octoolo and its row says so.
Is 320 kbps worth the extra space?
For music you will listen to closely, yes: it leaves the most margin. For speech, 128 kbps (64 for mono) is plenty and takes a fraction of the room.
Will a car stereo read these MP3s?
Almost certainly. A 44.1 or 48 kHz MP3 at a constant 128 to 320 kbps is exactly what car stereos, USB players and phones are built for.
WAV to MP3, and 16 more apps.
Download for Windows7 days free, then from $3.99 a month for all 17 apps. Windows 10 and 11.