Replace Audio Track in Video

Swap a video's audio track with music, voiceover, or silence — preserves 100% video quality via stream-copy. Browser-only via ffmpeg.wasm.

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About Replace Audio Track

Replace or add audio tracks to video — for content creators dubbing TikTok clips with copyright-safe music, podcasters fixing a botched recording with a clean re-take, teachers replacing student names with bleeps in lecture clips, or anyone who realized their phone captured wind noise instead of clean dialogue. Most apps re-encode the video to swap audio, wasting hours and degrading quality. This tool uses ffmpeg.wasm's stream-copy mode: the video stream is copied byte-for-byte (no re-encoding, no quality loss, no waiting), only the audio is processed. Result: a 5-minute 1080p video swaps audio in 10-30 seconds versus 5-15 minutes in a re-encoding tool. Supports MP4/WebM/MOV video and MP3/AAC/WAV/OGG/FLAC audio. Loop short audio or trim long audio to match video duration.

What file formats are supported?

Video: MP4, WebM, MOV. Audio: MP3, AAC, WAV, OGG, FLAC, and other common audio formats.

Can I add music to a video without audio?

Yes! You can add audio to videos that don't have an audio track, or replace the existing audio with new audio.

What if the audio is shorter than the video?

You can choose to loop the audio to match the video length, or leave it as-is (video will be silent after audio ends).

What if the audio is longer than the video?

You can choose to trim the audio to match the video length, or keep the full audio (video will end while audio continues in some players).

Replace Audio Track in Video — Swap a video's audio track with music, voiceover, or silence — preserves 100% video quality via stream-copy. Browser-onl — **Replace Audio Track in Video**

Will this affect video quality?

No, the video stream is copied without re-encoding, preserving 100% original video quality. Only the audio is processed.

Is my data safe?

Absolutely! All processing happens directly in your browser using FFmpeg.wasm (WebAssembly). Your files are never uploaded to any server. Everything stays private on your device.

Can I preview before downloading?

Yes! After processing, you can preview the video with the new audio track before downloading.

How long does processing take?

Processing time depends on video length. Since we're copying the video stream (not re-encoding), it's typically fast - usually 10-30 seconds for a 5-minute video.