WAV to MP3
Handheld recorders and audio interfaces write big WAV files. MP3 cuts the size by roughly ten times, which matters when you are uploading or emailing a long recording.
Free tool
Convert audio to MP3, WAV, FLAC, and six other formats on your own computer. No upload, no account, no file-size limit.
Free, v0.1.4. Drag your files in, pick a format, and convert.
macOS builds currently support Apple Silicon (M1 and later) only. Intel Mac and Linux builds are not available yet.
Overview
Audio Converter is a free desktop app for Mac and Windows that converts audio files to MP3, WAV, FLAC, OGG, Opus, M4A, AAC, WMA, AIFF. It handles a whole batch at once, runs entirely on your own machine, and works without an internet connection. Converted files land in the same folder as the originals, so there is no download step and nothing to go hunting for afterwards.
Step by step
Download Audio Converter for Mac or Windows and run the installer. There is no account to create and nothing to configure.
Drag files onto the drop zone, or click "Choose files..." to browse. Add as many as you want. They queue up as a list.
Choose an output format from the "Convert to" menu and click "Convert all". The menu groups formats Archivist accepts for session uploads (M4A, MP3, Opus, WAV) separately from the rest, so it is easy to pick a safe one if that is where the file is headed next. Each finished file is saved beside the original, and existing files are never overwritten.
Privacy
Most free online audio converters make you upload your file to someone else's server, wait for it to process, then download the result. That is slow, and your audio passes through a third party on the way. Audio Converter runs the whole conversion locally with a bundled engine, so there is no upload, no file-size limit from a web form, and no copy of your audio anywhere but your own drive.
Add one file or a whole batch, choose an output format, and go.
Files are converted on your machine and never transmitted anywhere.
Convert a four-hour recording without a web upload cap slowing you down.
Formats
Every format uses a fixed, sensible encoder setting, so there are no quality sliders to get wrong. Here is exactly what each one produces.
| Format | Encoder | Quality | Best for |
|---|---|---|---|
| MP3 | LAME | Variable bitrate, about 190 kbps | Sharing, uploads, and playback on anything |
| M4A / AAC | AAC | 192 kbps | Apple devices, and smaller files than MP3 at similar quality |
| Opus | libopus | 128 kbps | Speech and long recordings, at the smallest file size |
| OGG | Vorbis | Variable bitrate, about 160 kbps | Open-format playback in games and on the web |
| FLAC | FLAC | Lossless, compressed | Archiving a master copy without losing quality |
| WAV | 16-bit PCM | Lossless, uncompressed | Editing software and transcription tools that want raw audio |
| AIFF | 16-bit PCM | Lossless, uncompressed | Mac audio editing workflows |
| WMA | WMA v2 | Encoder default | Older Windows software that only reads WMA |
Files you can open: MP3, WAV, FLAC, OGG, Opus, M4A, AAC, WMA, AIFF, AIF. Video files such as MP4 and MOV are not accepted yet.
Common conversions
Handheld recorders and audio interfaces write big WAV files. MP3 cuts the size by roughly ten times, which matters when you are uploading or emailing a long recording.
Voice Memos on iPhone and Mac saves M4A. MP3 is the safer choice when you need a file that opens in older software without complaint.
FLAC keeps every bit of the original, at a size most tools would rather not deal with. MP3 is the practical copy to hand around.
Editing suites and transcription tools often want uncompressed audio. WAV gives them raw 16-bit PCM to work with.
WMA is a dead end outside older Windows software. MP3 plays anywhere, so this is usually a rescue job on an old archive.
Opus fits hours of speech into very little space. It is the right pick for talk-heavy recordings you want to keep but rarely replay.
FAQ
Yes. Audio Converter is a free desktop app for Mac and Windows, with no account, no subscription, and no cap on how many files you convert. It is an early release (v0.1.x), so expect the occasional rough edge while it matures.
No. Audio Converter does the whole conversion on your computer using a bundled ffmpeg engine, so your files never leave your device or touch a server. That also means there is no upload wait and no file-size cap imposed by a web service.
Audio Converter writes MP3, WAV, FLAC, OGG, Opus, M4A, AAC, WMA, AIFF. You pick one output format per batch from the "Convert to" menu, and every file in the queue is converted to it.
Audio Converter accepts MP3, WAV, FLAC, OGG, Opus, M4A, AAC, WMA, AIFF, AIF files. Anything outside that list is ignored when you drop it in, so if a file does not appear in the queue, its format is not supported yet.
Not currently. Audio Converter only accepts audio files, so video files such as MP4, MOV, and MKV are ignored if you drop them onto the window.
Yes. Drag in as many files as you like and they queue up as a list. Clicking "Convert all" works through the queue one file at a time, showing the status of each, so you can start a large batch and leave it running.
Audio Converter saves each converted file in the same folder as the original, under the same name with the new extension. Nothing is overwritten: if a file of that name already exists, the new one gets a number added, like "session (1).mp3".
Yes. The conversion engine is bundled inside the app, so once Audio Converter is installed it works fully offline. You only need a connection for the initial download.
MP3 output uses the LAME encoder at variable bitrate quality 2, which averages roughly 190 kbps, high enough that most people cannot tell it from the source. The settings are fixed in this release, and there are no quality controls to adjust yet.
For a multi-hour recording you plan to share or upload, MP3 is the safe default because everything plays it. If size is the main concern and the recording is mostly speech, Opus produces a much smaller file at similar clarity. Use FLAC only when you want to archive a lossless master copy.
The Mac build is signed and notarized by Apple. The first time you open it, macOS may still show the standard "developer cannot be verified" prompt simply because the app came from outside the App Store. Right-click (or Control-click) the app, choose "Open," then "Open" again, or go to System Settings → Privacy & Security and click "Open Anyway." On Windows the installer is not yet signed with a paid certificate, so SmartScreen may warn on first run. Click "More info," then "Run anyway."
Apple Silicon Macs (M1 and later) and 64-bit Windows 10 and 11 today. Intel Mac and Linux builds are not yet available.
Release notes and every download asset are on GitHub. Also try the free battle map grid overlay, VTT token generator, or dice and damage calculator.
Convert your session audio to MP3, then upload it to Archivist AI and get back recaps, timelines, and a searchable campaign history. See how it works.