Merge Audio Files with the ffmpeg concat Filter

Combine multiple MP3/M4A/WAV parts into one track — v=0:a=1 means audio only, single output.

WindowsaudiomediaffmpegLow risk
Run `ffmpeg -i part1.mp3 -i part2.mp3 -filter_complex "concat=v=0:a=1" merged.mp3` to join two audio files.

01Command

Command
$ ffmpeg -i part1.mp3 -i part2.mp3 -filter_complex "concat=v=0:a=1" merged.mp3

02What it does

The concat filter's v=0:a=1 setting tells ffmpeg to expect no video streams and produce exactly one audio output, stitching the inputs back to back. Add more -i inputs and raise the n= segment count (e.g. concat=n=3:v=0:a=1) to merge three or more files. For dozens of same-codec MP3s, the concat demuxer with a playlist file is faster since it avoids re-encoding.

03Risk

RiskLow risk
Requirementsffmpeg installed (winget install Gyan.FFmpeg).
!Warning: Mixing very different sample rates in one concat call can sound wrong — convert to a common rate first if needed.

04Undo

✓No undo needed — this command does not change persistent state.

05Sources

Last verified: 2026-09-19 · Category: Media

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