Why this tool is useful
Swap narration, music or ambience on a private short clip while making the absence of the original track explicit.
Local File Tools · runs locally
Private Video Audio Replacer
Replace a short browser-decodable video's original soundtrack with one selected audio file and export a real WebM without uploading either source.
Ready. Your working data stays in this browser.
Files and capture streams stay on this device. Processing uses browser APIs only; nothing is uploaded to YTSave, the media API or a proxy.
How it works
The browser decodes the selected sound with Web Audio, discards the video's original audio, pairs the new track with locally drawn frames and records WebM.
Practical example
Select one five-second video and one voice-over, replace the soundtrack at 100% volume and verify both source names before downloading.
Validation
The calculation is deterministic and explains validation errors instead of silently changing invalid input.
Privacy boundary
Input and output remain in this tab. Copy and download happen through browser APIs without a server upload.
Result passport
Every run reports its tool mode, timestamp and input/output size so transformed data can be audited.