Add Background Music to Video Online
Upload your video and music files and merge them into an MP4 with background music in one click. Supports music looping and auto-truncation. Browser-based, no upload, privacy protected.
Privacy Protection
All processing is done locally in your browser. Neither the video nor the music file is uploaded to any server.
Smart Loop
Automatically loops music when shorter than the video; auto-truncates when music is longer than the video
Format Compatible
Supports MP4/WebM/MOV video and MP3/AAC/WAV/OGG audio, outputs highly compatible MP4
Step 3: Configure Options
When music exceeds the video duration, automatically truncate it to match the video length
Use Cases
- Short video scoring: Add background music to Vlogs, travel videos, and daily life recordings
- Birthday/anniversary videos: Add your favorite music to family videos for a special touch
- Course/presentation videos: Add light music to screencasts or tutorials for a better viewing experience
- Promotional videos: Replace original audio with brand-appropriate background music
- Social media content: Add trending music to silent videos for greater reach
About This Tool
The background music tool is powered by WebCodecs technology and runs entirely in your browser. It reads your uploaded video track and music audio, merging them into a new MP4 file. No files are uploaded to any server, protecting your privacy. Supports MP3, AAC, M4A, WAV and other common audio formats, as well as MP4, WebM, MOV video formats. Output is H.264 MP4 for maximum compatibility.
Frequently Asked Questions
Will video quality degrade after adding background music?
No. The video track uses stream copy technology to directly preserve the original encoded data, so the video quality is identical to the original file. Only the background music will be re-encoded as a new audio track.
What audio formats are supported?
Supports MP3, AAC, M4A, WAV, OGG and other common audio formats. Audio tracks embedded in video files (e.g. AAC audio in MP4) can also be used as background music sources.
What if the music is shorter than the video?
Enable the "Loop Playback" option and the music will automatically loop until it covers the entire video duration, ensuring background music plays throughout.
Will the original video audio be preserved?
This tool fully replaces the original video audio track with the music file. To preserve the original audio, use the "Extract Audio" tool first to save it, then mix using another tool.
Will my files be uploaded to a server?
No. Everything happens locally in your browser — your files never leave your device, keeping your privacy fully protected.