SOLVORY MEDIA LAB · ADVANCED TOOL
Add Music & Replace Audio in Video
Add a soundtrack to video, replace the existing audio or blend music with original sound, adjust levels, start delay, fades and export a synchronized MP4.
Make your media work beautifully.
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Professional controls
Adjust before export
Choose your source media to get started.
PREVIEW
How to add audio to video online
Replacing the soundtrack removes the original sound; mixing combines tracks at adjustable levels. Use music you have rights to use. The editor processes supplied audio, not external streaming URLs.
- Upload a video, then select one owned soundtrack or narration file.
- Choose Replace or Mix, music volume, start delay and optional fades.
- Review audio synchronization, render MP4 and listen to the complete output.
Music mixing needs explicit choices
Replacing the soundtrack removes the original sound; mixing combines tracks at adjustable levels. Use music you have rights to use. The editor processes supplied audio, not external streaming URLs. This workspace uses browser-local media codecs for output creation. First-time processing may require downloading a sizable WebAssembly engine; conversion speed, available encoders and supported formats depend on the device, source file and browser. Review the exported video or audio before relying on it professionally.
Helpful next steps
For complementary workflows see our Video Compressor, Audio Trimmer, Video Trimmer and all video tools. Read the FFmpeg command-line documentation for the fundamentals of codec choice, filtering and mapping, and ffmpeg.wasm architecture documentation for browser execution constraints.