Free tool

Free Audio Converter

Change any audio file into MP3, WAV, M4A, FLAC or OGG. The converter reads the formats phones, recorders, messaging apps and studios produce, and it runs on your own device, so there is no upload queue and no file leaves your hands.

01 — Your file

Choose a file

02 — Result

Your converted file

Choose a file and press Convert to MP3. The conversion runs in this tab, so even large files never leave your computer or phone.

Converting an audio file

  1. Open the file with the box above. The tool identifies the codec, sample rate and length.
  2. Choose the output format and, for MP3, M4A or OGG, a quality level.
  3. Convert, preview the result on the page, and download it.

Formats it reads

The converter is built on ffmpeg, so it opens far more than the usual suspects. Formats tested on this page include MP3, WAV, M4A (AAC and Apple Lossless), AAC, FLAC, OGG Vorbis, Opus voice notes, AMR call recordings and the sound inside 3GP, MP4, MOV, MKV and WebM files. If a file opens and shows a sound codec on the file card, it will convert.

Choosing the output

MP3
For playing and sharing anywhere. Choose 128 kbps for speech and 192 to 320 kbps for music.
M4A
Smaller than MP3 at the same quality, native on Apple devices. AAC sources are copied without loss.
WAV
For editing and for software that only accepts uncompressed audio. Large.
FLAC
Lossless and smaller than WAV. The right choice for archiving.
OGG
Open format preferred by some games, Linux software and web projects.

A common mistake is converting a lossy file such as MP3 into WAV or FLAC to "improve" it. That only makes the file bigger. Lossless output protects quality from here on; it can't bring back what earlier compression removed. Go the other way, from WAV or FLAC to a lossy format, whenever you need a smaller file.

Single-purpose pages

If you already know the job, the dedicated converters explain the details of each format: M4A to MP3 for iPhone voice memos, Opus to MP3 for WhatsApp voice notes, AMR to MP3 for call recordings and WAV to MP3 for shrinking studio files.

Converting for transcription

mydubly's audio to text tool accepts MP3, WAV, M4A, AAC, OGG and FLAC. If your recording is in another format, convert it to MP3 here first, then upload it for a timestamped transcript.

How the free converter works

The converter is ffmpeg, the open-source media toolkit, compiled to WebAssembly so it runs inside your browser tab. Your file is read straight from your disk by that engine; it is never uploaded to mydubly or anywhere else, and no account is needed.

  • The engine is about 30 MB and downloads the first time you convert something. After that your browser normally keeps it.
  • Large inputs are fine because the file is read in place, but the result is built in memory, so outputs are capped at about 1.5 GB.
  • Speed depends on your device. Copying streams takes seconds; re-encoding video is the slow case.
  • Keep the tab open until the download button appears. Closing it stops the conversion.

More free tools

Turn the file into text

Frequently asked questions

Is this audio converter free?

Yes, with no sign-up, no watermark and no limit on the number of files. It runs on your device, so it costs nothing to operate.

Which format should I convert audio to?

MP3 if you want a file that plays everywhere, M4A for smaller files on Apple devices, FLAC to archive without loss and WAV for editing.

Does converting audio lose quality?

Converting to MP3, M4A or OGG re-encodes the sound, which loses a little. WAV and FLAC lose nothing further. Copying AAC into M4A loses nothing.

Can I convert audio on my phone?

Yes, in a current mobile browser. Choose the file from Files or your recordings, convert, and save the result.