FFmpeg Cookbook

Audio Converter

Convert audio files between MP3, WAV, AAC (M4A), FLAC, and OGG Opus. Choose a bitrate for lossy formats; WAV and FLAC stay lossless.

Local processing only — your file never leaves the browser
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Drag & drop an audio file, or tap to select
MP3 / WAV / M4A / AAC / FLAC / OGG / Opus, up to 200 MB
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Lossy (MP3 / AAC / Opus) shrinks the file using a bitrate you pick — 192 kbps is transparent for most music. Lossless (WAV / FLAC) preserves the exact audio; the bitrate selector is ignored. Re-encoding a lossy file to a higher bitrate does not restore quality.
Converting… 0%

What this tool does

  • Five output formats: MP3, AAC/M4A, OGG Opus (lossy) and WAV, FLAC (lossless)
  • Pick 128 / 192 / 256 / 320 kbps for lossy formats; the bitrate field is disabled automatically for WAV and FLAC
  • Accepts MP3, WAV, M4A, AAC, FLAC, OGG, and Opus inputs up to 200 MB
  • Preview the converted audio in the browser before downloading
  • Runs locally with ffmpeg.wasm — your file never leaves your device, nothing is uploaded

How to use

  1. 1

    Drop an audio file

    Drag & drop or tap to select any common audio file, up to 200 MB.

  2. 2

    Choose the output format

    MP3 for universal playback, AAC/M4A for Apple, OGG Opus for the smallest size at a given quality, WAV/FLAC to stay lossless.

  3. 3

    Pick a bitrate (lossy only)

    192 kbps is transparent for most music; 320 kbps for archival lossy; 128 kbps for voice or small files.

  4. 4

    Convert and download

    Conversion runs in your browser. Preview the result, then download.

What each setting means

Output format
The container/codec to write. MP3 (libmp3lame) and AAC are the most compatible; Opus is the most efficient lossy codec; WAV is uncompressed PCM; FLAC is lossless but ~50–60% the size of WAV.
Bitrate
How many kilobits per second a lossy codec may use. Higher = better quality and larger files. Ignored for WAV/FLAC, which are lossless.

Recommended settings

Music for everyday listening
MP3 192 kbps
Transparent for most ears, plays everywhere.
Smallest file at decent quality
OGG Opus 128 kbps
Opus beats MP3/AAC at low bitrates.
Apple ecosystem / iMovie
AAC (M4A) 256 kbps
Native to Apple devices and editors.
Editing master / archival
FLAC
Lossless, but roughly half the size of WAV.

Common pitfalls

Symptom: Converting MP3 → WAV/FLAC did not improve the quality

Cause: Quality lost in the original lossy encode is gone permanently. Re-encoding to lossless only makes the file bigger.

Fix: Go back to the original lossless or highest-bitrate source if you need better quality.

Symptom: The output sounds the same but the file is much bigger

Cause: You raised the bitrate above the source bitrate, or converted lossy → lossless.

Fix: Match or stay below the source bitrate; there is no benefit to exceeding it.

Symptom: A very large file is slow or runs out of memory

Cause: Everything runs in the browser tab, so memory is limited.

Fix: Keep files under ~200 MB; trim long recordings first if needed.

Equivalent FFmpeg commands

Reference commands you can run on the desktop FFmpeg CLI.

WAV → MP3 192 kbps
ffmpeg -i input.wav -vn -c:a libmp3lame -b:a 192k output.mp3
Any → AAC (M4A) 256 kbps
ffmpeg -i input.flac -vn -c:a aac -b:a 256k output.m4a
Any → OGG Opus 128 kbps
ffmpeg -i input.mp3 -vn -c:a libopus -b:a 128k output.ogg
Any → FLAC (lossless)
ffmpeg -i input.wav -vn -c:a flac output.flac

Browser support & limits

  • Runs in the browser, so very large files are limited by available memory (keep under ~200 MB).
  • Audio-to-audio only — use the Audio Extractor for pulling audio out of a video.

Privacy

This tool runs ffmpeg.wasm directly in your browser. Files never leave your device — everything runs locally. Read the privacy policy →

Frequently asked questions

Is my audio uploaded anywhere?

No. Conversion runs entirely in your browser via ffmpeg.wasm. The file never leaves your device and nothing is sent to a server.

Which format should I choose?

MP3 for maximum compatibility, AAC/M4A for Apple devices, OGG Opus for the smallest size at a given quality, and WAV or FLAC when you must keep lossless quality (e.g., for further editing).

Does converting to a higher bitrate improve quality?

No. You cannot recover detail that a previous lossy encode discarded. A higher bitrate only makes the file larger. Always start from the best-quality source you have.

What is the difference between WAV and FLAC?

Both are lossless. WAV is uncompressed PCM and large; FLAC compresses the same audio to roughly 50–60% of the size with no quality loss. Use FLAC unless a tool specifically needs WAV.

Why is the bitrate selector greyed out?

WAV and FLAC are lossless formats that do not use a target bitrate, so the selector is disabled when you pick them.

Can it convert the audio inside a video file?

This tool is for audio-to-audio conversion. To pull the audio track out of a video, use the Audio Extractor tool instead.

Related tools

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