Adding a soundtrack or swapping a clip's audio normally means a timeline editor and dragging tracks around. Supercut does it differently: you type what you want. You load the music as a second clip, name it in a plain-English prompt, and Supercut maps that audio onto your video. Everything runs in your browser, so your footage and your music never get uploaded.
Adding music and replacing audio are the same underlying move in Supercut: you point the video at a new audio source. If your clip is silent (B-roll, a screen recording, muted phone footage), pointing it at a music file simply gives it a soundtrack. If the clip already has sound you do not want, the same step swaps it: Supercut maps the new track on and the old audio is replaced. The swap replaces the track rather than layering a second one over the original, so when you want a clean music bed, mute or remove the original audio first, then bring in the music as the new track.
When you replace audio, Supercut copies your video stream verbatim and re-encodes only the audio. Your picture is untouched: no second-generation video compression, no visible quality loss. The deterministic engine maps your chosen audio onto the video and trims to the shorter of the two so you do not end up with stalled video or trailing silence. Because the work happens locally with WebAssembly, the only thing that ever leaves your device is the text of your prompt, never the video or the music.
Plain-English follow-up prompts cover the common fixes. If a song is too loud over a voiceover, run a volume adjustment after the swap, like "lower the music a bit" or "raise the volume." To soften a hard musical entrance or ending, ask for a fade. If the track is longer than the clip, trim the video first so the audio lines up with the section you care about, then run the swap on the trimmed clip. Supercut maps the new audio to the shorter stream, so a trimmed video gives you precise control over where the music sits.
Go to the Supercut editor and drop your video onto it. It loads straight into your browser as a clip. No account is needed to try your first export, and nothing is uploaded to a server.
Drop the song, voiceover, or audio-bearing clip into the same editor. It loads as a second clip alongside your video, and you can reference it by name in a prompt.
Tell Supercut to use the new audio. Reference your audio clip with @, for example "use audio from @music." On a silent clip this gives it a soundtrack; on a clip that already has sound this swaps the track. To clear the original first, say "remove the audio" before the swap.
Supercut runs the edit locally and plays it back. Check that the music starts where you expect and that voices and music sit at the right levels. Refine with follow-up prompts like "lower the music" or "add a 1 second fade out."
When it sounds right, export. The video stream is copied as-is and only the audio is re-encoded, so picture quality stays intact. The finished file downloads to your device, having never left your browser.
Swap a video’s audio track with music or voiceover from another clip, in your browser. Video stays untouched, nothing uploads.
Mute a video or strip its soundtrack in your browser. Remove audio without uploading, perfect before adding your own music or voiceover.
Make a quiet video louder or tame loud audio in your browser. Adjust volume in dB without uploading your clip.
Reframe to 9:16, add viral captions, trim hooks, and export TikTok-ready clips in your browser. No upload before you post.
Reframe, caption, and batch-process client clips in your browser. No uploading client footage to a third party, and no watermark on paid exports.
No. Supercut processes everything in your browser with WebAssembly. Your video and your audio clip never leave your device. Only the text of your prompt is sent, so the AI knows what edit to plan.
No. The video stream is copied verbatim and only the audio is re-encoded, so your picture stays at full quality.
The audio swap replaces the track rather than layering a second one. For a clean music bed, mute or remove the original audio first, then add the music. If you need to balance two sources, adjust volume with a follow-up prompt.
Common formats work, including MP4, MOV, and WebM for video and standard audio files for the soundtrack. You can also extract or convert audio as MP3 inside Supercut if you need a specific format.
You can try your first export with no account. Unlimited watermark-free exports and every tool are part of the paid plan, which starts at 4.99 per month billed yearly (59.88 per year), with a 9.99 monthly option and a 199 one-time lifetime option. You can cancel anytime.