How to remove background noise from a video

Background noise is the fastest way to make good footage feel amateur. Hiss, hum, fan rumble, and room tone bury the voice and pull attention from what is being said. With Supercut you clean up the audio by typing a plain-English prompt, and the whole process runs in your browser, so your recording is never uploaded.

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What background noise actually is

Most unwanted sound falls into two buckets. The first is steady, broadband noise: tape hiss, electrical hum, air conditioning, computer fans, and general room tone. This kind sits under everything at a constant level, and it is the easiest to reduce because software can learn its profile and pull it down. The second bucket is sudden, irregular sound: a door slam, a cough, traffic, a notification ping. Steady noise responds well to cleanup. Irregular noise is harder, and the most reliable fix for a one-off sound is to trim that moment out instead of trying to erase it.

How Supercut cleans audio in your browser

Supercut is a prompt-based editor. You describe the edit in plain English, an AI plans it, and a deterministic engine maps that plan to FFmpeg operations that run locally through WebAssembly. For noise, that means the cleanup happens on your own device. Your footage and its audio are never sent to a server. Only your text prompt leaves the page, so the AI knows what you want done. The result is clearer speech with the constant background layer pulled down, exported as a normal video file.

Get the cleanest result possible

Cleanup goes further when you stack a few prompts in order. After reducing noise, ask Supercut to normalize the volume so the voice lands at a steady level once the background layer drops. If dead air at the start or end is where the hiss is most obvious, trim those seconds out. And if a single loud event ruins one stretch, cutting that slice is more dependable than fighting the sound itself. Clean, then normalize, then trim, all from plain-English prompts in a row.

Step by step

  1. 1

    Open Supercut and drop in your clip

    Go to Supercut in your browser and add the video with the noisy audio. It loads locally on your device. Nothing is uploaded.

  2. 2

    Type a plain-English prompt

    Ask for the cleanup in your own words, for example "clean up the audio and reduce background noise." The AI plans the edit and the engine applies it on your device.

  3. 3

    Preview the cleaned audio

    Play it back and listen for clearer speech with the hiss or hum pulled down underneath it. Want more? Follow up with another prompt like "normalize the volume" or "trim the first three seconds."

  4. 4

    Export your clip

    When it sounds right, export. The cleaned video is rendered locally and saved to your device, with your footage and audio never having left your browser.

Tips

  • Steady noise like fans, hum, and hiss cleans up best. For a one-off sound like a cough or door slam, trimming that moment out is more reliable than trying to erase it.
  • Pair noise reduction with a "normalize the volume" prompt so the voice stays at a steady level after the background layer comes down.
  • Work offline if you like. Once the page has loaded, you can keep editing without a connection.
  • Record in the quietest space you can to begin with. Cleanup reduces noise, but it cannot fully replace a clean source.

Do it in Supercut

Related use cases

Frequently asked questions

Is my video uploaded when I remove the noise?

No. Audio cleanup runs in your browser through WebAssembly, so your footage and its audio stay on your device. Only your text prompt is sent, so the AI knows what edit to plan.

What kinds of background noise can it reduce?

Steady, constant noise is the best candidate: hiss, electrical hum, air conditioning, fan noise, and general room tone. Sudden one-off sounds are harder, and trimming that moment out is usually the better fix.

Will reducing noise make the voice sound worse?

Heavy noise reduction can thin out a voice, so Supercut aims for a clearer result without overprocessing. If the voice ends up uneven, follow up with a "normalize the volume" prompt to even it out.

Do I need to install anything or create an account?

No install, it runs in your browser. You can try your first export without an account. Unlimited watermark-free exports and every tool come with a paid plan, from 4.99 a month billed yearly, 9.99 monthly, or 199 one-time lifetime.

Can I remove the audio entirely instead of cleaning it?

Yes. If the audio is beyond saving, you can ask Supercut to mute or remove the audio, or replace the track with new audio, all from plain-English prompts.