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Add music to a video free, no watermark

By ShinobiTools Team · Last updated: August 2026

Pick your video and your music together and get the video back with the music under it — original sound replaced, or kept with the music mixed underneath. No watermark, no account, free.

Replace the sound, or mix under it

Two modes, one honest difference. Replace throws the original sound away — right for slideshows, drone shots and gameplay where the original audio is wind or fan noise. Mix keeps the original and lays the music under it at 30% volume — right for talking videos where the voice must stay understandable. If the music itself has vocals, pulling those out first with StemGrab's instrumental maker keeps two voices from competing under your narration.

Either way the video keeps its full length: shorter music runs out into silence, longer music is cut at the video's end. And the picture is copied through untouched — no re-encode, no quality loss, no watermark.

Just need the sound gone, without new music? That's remove the audio. Music too loud or too quiet afterwards? Change the volume.

Picking the two files

Select both files in one go — the video and the music (MP3, WAV, FLAC or M4A), holding Ctrl (Cmd on a Mac) in the file dialog. The tool works out which is which by itself.

Up to 400 MB per file, and the whole thing runs on our own server: uploaded, combined, sent back, deleted.

Common questions

Is this free, with no watermark?

Yes — no watermark, no account, no daily cap. Up to 400 MB per file.

Does the video lose quality?

No. The picture is copied through bit-for-bit; only the sound track is rebuilt.

What if the music is shorter or longer than the video?

The video always keeps its full length: shorter music runs out into silence, longer music is cut when the video ends.

Can I keep the original voices and add music underneath?

Yes — that's the mix mode: original sound stays at full volume, the music sits under it at 30%.

Which audio formats work as music?

MP3, WAV, FLAC and M4A, up to 400 MB and 20 min.

What happens to my files?

Combined on our own server, sent straight back, and both uploads are deleted the moment the job finishes.