Add Audio to Video Online for Free
Upload a video and an audio file, then download a new video with the added audio as a separate track.
Upload video and audio
Append a new audio track to your video while keeping the original video, audio, and subtitle tracks where possible.
Hints
- Wait for the current download to finish before starting another add audio job, or it may fail.
- Very large files may take longer or fail on memory-limited browsers or devices.
Status: Ready
How to use
- 1 Choose a video file from your device.
- 2 Choose the audio file you want to add.
- 3 Click Add Audio.
- 4 When processing finishes, click Download.
Supported formats
Video input
Audio input
Output
Separate audio track
The added sound becomes its own track, so the original audio can remain available in supported players.
Keeps original streams
The tool preserves the existing video and other tracks where the output format supports them.
No cloud upload
Your video and audio files stay on your device while the browser prepares the download.
Frequently asked questions
Does this replace the existing audio?
No. The tool adds the new audio as another track and keeps existing tracks where the output format supports them.
Will the video picture be re-compressed?
Usually no. The tool keeps the original video stream where possible, so adding audio does not normally add another generation of video compression.
Why can the added audio change format?
Some video formats only accept certain audio types, so the newly added audio may be prepared for the selected video container while the original streams are preserved where possible.
Are my files uploaded?
No. Processing runs in your browser, so your video and audio files are not uploaded to a server.
Related tools
Need large files, batch audio adding, or more track controls?
The online tool is convenient for quick track additions. For bigger jobs, Brivotech Video Converter gives you a faster desktop workflow with large file support, batch processing, offline work, and more control over video outputs.
Large video support
Work with files that are too big or slow for browser-based processing.
Batch workflows
Prepare multiple videos without repeating the same browser steps.
Offline and private
Process media locally on your computer without uploading videos to the cloud.
More output control
Use a desktop workflow when you need repeated exports and heavier media tasks.