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Add Audio to Video

Drop one video and one audio file; the audio becomes the new soundtrack, trimmed to the video's length.

Browser-first · upload only when a format needs it

Drop one video and one audio file; the audio becomes the new soundtrack, trimmed to the video's length.

Opens MP3 · WAV · M4A · FLAC · OGG · AAC · MP4 · WEBM · MOV · MKV

This tool needs at least 2 files.

or drop files and folders hereUp to 500 MB per file on the free plan · older formats use the server encoderFolders are welcome

How it works

  1. 01

    Choose a file for Add Audio to Video. It accepts MP4, MOV, WEBM, MKV, MP3, WAV, FLAC, OGG, M4A. Most files stay in this tab.

  2. 02

    Set the options on the workbench — preview, crop or timeline when this tool has one — then press Run.

  3. 03

    Download the result. It is also saved in your tray so the next tool can pick it up without another upload.

About this tool

Add a video and an audio file (MP3, WAV, M4A, FLAC or OGG). The video stream is copied without re-encoding and the audio is encoded into a new track that ends where the video ends. The original soundtrack is replaced — use Mute Video first if the clip has sound you want gone, or Change Video Volume afterwards to balance the result.

Questions

What can I open in Add Audio to Video?
Add Audio to Video accepts MP4, MOV, WEBM, MKV, MP3, WAV, FLAC, OGG, M4A. Older video containers such as AVI, WMV, FLV, MPEG and 3GP are decoded by the server encoder.
Does Add Audio to Video upload my file?
Most MP4, WebM, images and PDF stay in this tab. Instagram/TikTok crops, DVD, GIF, iPhone presets, stabilize, hard containers (AVI, WMV, HEVC) and a failed local encode go to the server encoder. The file is processed and discarded — we do not keep a copy.
How large can the file be?
Free: 500 MB and 8 exports a day. Plus (waitlist) raises the daily cap. A pasted public file URL is also accepted.

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