FREE · VIDEO TOOLS
Video Audio Replacer.
Replace a video audio track with a selected local recording.
The first run loads a 31 MB engine from PasteZap. Your selected files stay on this device. Short clips work best, particularly on phones.
How to use Video Audio Replacer
Choose local files, adjust the settings, explicitly load the local media engine and process. Preview and check the output before downloading.
How it works
Replace a video audio track with a selected local recording. Files are never sent to a conversion service. The single-thread FFmpeg engine runs in a local worker and can be cancelled. Numeric trimming, cropping and file-order controls are used. Video merging exports silent 640×360 clips; audio replacement uses the shorter duration. Center cancellation is not AI stem separation. Watermarks use the bundled Liberation Sans font; complex-script shaping and colored emoji are not guaranteed. Loudness normalization uses FFmpeg loudnorm, but very short clips may not reach the target precisely.
Example
Video first, replacement audio second → combined MP4
Questions about Video Audio Replacer
Is Video Audio Replacer free, and do I need an account?
Yes. This tool is free to use in your browser without an account. Processing takes place on your device.
What are the limits and what should I check?
50 MB total input; at most five files. Video/GIF: 120 seconds and 1920×1080 maximum; audio: 300 seconds. GIF reversal: at most 10 seconds and one megapixel. A 31 MB engine loads from PasteZap on first use. Processing has a two-minute time limit per operation. Output limit: 50 MB; re-encoding can reduce quality. Review the result before using it in your work.
Is my input sent to a server?
Your input is processed in your browser and is not uploaded by this tool. Files and pasted text are cleared when the page is refreshed. Normal website requests are still required to load the page and its libraries. Read the privacy explanation.