Filery

Add Audio to Video

Replace or mix an audio track into a video.

Choose video file or drop it anywhere on this page MP4 · MOV · WEBM · MKV · AVI · WMV · FLV · M4V · 3GP · MPEG · +3 Processed on your device — never uploaded

How to add audio to video

  1. Drop the video in, then add an audio file in the secondary drop zone.
  2. Choose replace (discard the original) or mix (blend both).
  3. Adjust volume levels and download.

About this tool

Adding a music track to a video, replacing a poorly recorded room tone with clean audio, or laying a voiceover over screen capture footage are all variations of the same operation: changing what the audio track contains. Replace mode is the simplest — the existing audio is discarded and the new track takes its place. Mix mode runs both signals through a gain-controlled sum, which is what you want for commentary over a clip where the original ambient sound should remain audible underneath.

The volume percentages are linear gain on the signal amplitude. 200% doubles the amplitude (+6 dB), 50% halves it. For more precise control, use the audio volume tool separately on the input audio before bringing it into this tool.

Questions

What audio formats can I add?
MP3, WAV, AAC/M4A, FLAC, OGG and Opus are all supported. The audio is decoded and then encoded into the output container, so the source format does not constrain you.
What happens if my audio is longer than the video?
The audio is trimmed to the video length by default, which usually gives the most natural result. If you want to shorten the video to match a specific piece of audio instead, choose the "trim video to audio length" option.