Add Audio to Video
Replace the soundtrack, mix music under the original, or mute the clip. The video is copied, not re-encoded. Millisecond timing, no upload, no watermark, no account.
Last updated: November 2, 2026
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Three ways to use it
Each mode has its own page with the steps, limits and questions for that job.
Weighing your options? Read how this tool compares with Kapwing, Clideo, VEED and 123apps: add-audio tools compared.
Why Use Submind's Add Audio to Video Tool?
Replace the soundtrack, mix music under the original, or mute the clip.The Video Never Leaves Your Device
The file is read, mixed and written inside the tab. No upload, no account, and no copy on a server.
The Picture Is Copied, Not Re-encoded
When MP4 can hold the video codec, the stream is copied packet by packet. Resolution, bitrate and colour stay exactly as they were.
Millisecond Timing
Set the audio start to the millisecond, trim it at the end of the video, or loop a short track to fill a long clip.
No Watermark, No Export Timer
Add or replace audio on a full-length video without a watermark, a 720p cap or a four-minute export limit.
How to Add Audio to a Video in 4 Steps
One video, one audio file, three ways to combine them.Select the Video
Drop an MP4, MOV, M4V, MKV or WebM file. The browser reads the duration, size and codec without uploading it.
Choose the Mode
Replace removes the original soundtrack. Add mixes the new track under it. Mute removes the audio and keeps the picture.
Place the Audio
Drop an MP3, WAV, M4A, FLAC or OGG file. Set the start to the millisecond, choose trim or loop, then balance the two levels.
Export the MP4
The video stream is copied and the audio is encoded to AAC. Small files download at once, large files save straight to disk.
Where This Tool Saves a Round Trip
Three jobs that used to need a video editor.Add Background Music
Lay a licensed track under a voiceover or a product clip. Lower the original audio and loop the music to fill the video.
Replace a Bad Recording
The picture is fine and the sound is not. Swap in a clean take without re-encoding the video or losing its resolution.
Mute a Clip
Remove a noisy room, a copyrighted song or an unwanted conversation. The audio track is dropped and the picture is untouched.
Level Up Your Workflow
Turn your audio into notes with Submind AI
Record a thought and get a clean transcript, a structured note, and the action items.
Add Audio to Video Questions
Modes, formats, timing and what happens to the picture.No. The browser reads the file from your device, copies the video packets and writes the new MP4 locally. Nothing is sent to a server.