Free tool
Free Audio Converter for Mac & Windows
Convert audio to MP3, WAV, FLAC, and six other formats on your own computer. No upload, no account, no file-size limit.
Download Audio Converter
Free, v0.1.3. 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
What Audio Converter Does
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.
- Price
- Free, with no account and no file limits
- Platforms
- Apple Silicon Macs (M1 and later) and 64-bit Windows 10/11
- Converts to
- MP3, WAV, FLAC, OGG, Opus, M4A, AAC, WMA, AIFF
- Accepts
- MP3, WAV, FLAC, OGG, Opus, M4A, AAC, WMA, AIFF, AIF
- Internet
- Not required — conversion runs offline
- Saved to
- The same folder as the original file
Step by step
How to Convert an Audio File
- 1
Install the app
Download Audio Converter for Mac or Windows and run the installer. There is no account to create and nothing to configure.
- 2
Add your audio files
Drag files onto the drop zone, or click “Choose files…” to browse. Add as many as you want — they queue up as a list.
- 3
Pick a format and convert
Choose an output format from the “Convert to” menu and click “Convert all”. Each finished file is saved beside the original, and existing files are never overwritten.
Privacy
Nothing Leaves Your Computer
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.
Drag, drop, convert
Add one file or a whole batch, choose an output format, and go.
Private by design
Files are converted on your machine and never transmitted anywhere.
No size limits
Convert a four-hour recording without a web upload cap slowing you down.
Formats
Output Formats and Quality
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
Which Conversion Do You Need?
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.
M4A to MP3
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 to MP3
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.
MP3 to WAV
Editing suites and transcription tools often want uncompressed audio. WAV gives them raw 16-bit PCM to work with.
WMA to MP3
WMA is a dead end outside older Windows software. MP3 plays anywhere, so this is usually a rescue job on an old archive.
Audio to Opus
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
Common Questions
Is this audio converter really free?
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.
Do my audio files get uploaded anywhere?
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.
Which audio formats can it convert to?
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.
Which audio files can it open?
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.
Can it extract audio from a video file?
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.
Can it convert several files at once?
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.
Where do the converted files get saved?
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".
Does it work without an internet connection?
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.
What bitrate does it convert MP3 files at?
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; there are no quality controls to adjust yet.
Which format should I use for a long recording?
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.
Why does macOS or Windows show a security warning when I open it?
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.”
Which operating systems are supported?
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. Need dice odds instead? Try the free dice and damage calculator.
Recording Your TTRPG Sessions?
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.