Add or replace background audio, optionally mix original sound, pad short tracks with silence and trim long tracks to the video duration.
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No registration · Free to useHow to use Add Audio to Video
- Choose files and inspect preview and input limits.
- Choose background audio up to 10 MB and decide whether to replace or mix the original.
- Generate, inspect the actual output and download; keep the source file.
Frequently asked questions
How do I add music or replace original video sound?
Upload video and select a background audio file. By default the added sound replaces the original; enable mixing to play both. Generate, check levels and duration, then download MP4.
How do I choose between mixing and replacing audio?
Mix when you want original speech with added music; leave mixing off for only the new soundtrack. Mixing does not detect speech or automatically duck music. Check levels and adjust the music beforehand if needed.
What happens when music is shorter or longer than video?
Output duration follows the video. Short audio is followed by silence, while audio beyond the video end is cut off. Music is not automatically looped.
Can I add music to a silent video?
Yes. The selected audio becomes its soundtrack without requiring an empty track first. Audio starts at the beginning; there is no timeline control for an offset.
Does background music also have a 100 MB limit?
No. Video allows up to 100 MB, while the separate background audio is limited to 10 MB. Trim an oversized music track or convert it to a smaller MP3 first.
What size and duration limits apply to Add Audio to Video?
Video is limited to 100 MB, 10 minutes and a 1920 × 1080 pixel budget. The added audio has a separate 10 MB and 30-minute limit. Output is limited to 150 MB; video and audio sizes are checked separately.
Does Add Audio to Video require registration?
No account is required and the tool is currently free. Download results before closing or refreshing the page. Initial loading needs an internet connection; processing speed depends on the device and file size.