What kind of noise does it remove?

Steady background noise — hiss, hum, air-conditioner drone, fan and low-end rumble. It's tuned conservatively so speech stays natural rather than hollowed-out. It won't erase a one-off door slam, but constant background noise drops noticeably.

Is this the same as removing video noise or grain?

No — this cleans the AUDIO. To reduce visual noise or grain in the picture, use Enhance or the Low-light preset instead.

Is my video uploaded anywhere?

No. Crisp cleans the audio entirely on your Mac — nothing is uploaded, so there's no queue, no size cap, and your footage never leaves the device.

Guide · Remove background noise on Mac

How to remove background noise from a video on a Mac

A great clip with a hissy, humming, air-conditioner-in-the-background soundtrack is a shame. You don't need a DAW to fix it. Here's how to remove background noise from a video on a Mac in one tap, 100% offline: the picture is untouched, and there's no account, no upload.

Updated July 2026 · step-by-step

The fastest way: just ask

Crisp has a plain-English box ("Or just tell Crisp what to do…"). Drop your video in and type it:

reduce the background noise — clean up the audio
remove the hiss — knock down constant hiss
get rid of the hum — clear an electrical/AC hum
clean up the audio — general noise reduction

Crisp reads the request, switches to the Audio lane's Denoise mode, and you just press the button.

Step by step: the Audio lane

Open Crisp and drop in your video

Get the free Crisp app for Mac and drag your clip onto the window. Nothing is uploaded: the whole job runs on your Mac.
select the clip and use Audio in the Tools panel, then Denoise

In Crisp, select the clip on your timeline and use Audio in the Tools panel. Or just type “remove the background noise” in the prompt bar — Crisp maps plain English to the same tool.
Press it

Crisp runs a noise reducer over the audio and clears low-end rumble on-device. The picture is stream-copied untouched — only the audio is cleaned.
Save

The cleaned clip lands beside your original — with the video never re-rendered.

Great for constant noise — gentle on voices

Denoise targets the steady stuff: tape hiss, an electrical hum, an AC unit or fan, low-end rumble. It's tuned conservatively so speech and music stay natural rather than getting that underwater, over-processed sound. It won't erase a one-off door slam or a passing car, but a constant noise floor drops noticeably. Want the levels even too? Run Normalize after.

Audio noise vs video noise

Two different "noise" problems, two different tools:

Background noise in the sound — hiss, hum, AC drone. That's this guide: the Audio lane's Denoise mode.
Visual noise / grain in the picture — speckle in dark or low-light footage. For that, use Enhance / Low-light instead.

Crisp vs iMovie vs online noise removers

	Crisp	iMovie	Online noise removers
One-tap audio noise reduction	Yes	"Reduce background noise" slider	Yes
Plain-English request	Yes	No	No
Video not re-encoded	Yes (audio only)	Re-renders	Varies
100% offline, nothing uploaded	Yes	Yes	Uploads your clip
Price	Free tier + one-time $129	Free	Free + upsell

iMovie's noise slider re-renders the whole project; online tools upload your footage. Crisp cleans only the audio and keeps it local.

Why offline matters for audio cleanup

Your footage stays yours. The "remove background noise online" tools upload your clip first. Crisp cleans it entirely on your Mac.
Video untouched. Only the audio is processed — no quality loss on the picture, and it's fast.
No queue, no size cap. It works on the whole file locally.
Stack it. Denoise, then Normalize the levels — all on-device.

Clean up your audio — offline

Free to try on your Mac. One tap to knock down hiss and hum — no account, no upload, nothing leaves your device.

Download Crisp for Mac

Apple Silicon · macOS 12+ · Notarized

Background noise questions

How do I remove background noise from a video on a Mac for free?

Use Crisp: drop your clip in, select the clip and use Audio in the Tools panel, then choose Denoise (or type "reduce the background noise"), and press it. It cleans the audio on your Mac: no account, no upload.

What noise does it remove?

Steady background noise — hiss, hum, AC drone, fan, low-end rumble — tuned gently so speech stays natural. It won't erase one-off sounds like a door slam.

Does it change the video?

No — only the audio is processed; the picture is stream-copied, so there's no quality loss and it's fast.

Is this the same as removing video grain?

No — that's visual noise. For grain in the picture, use Enhance or the Low-light preset instead.

Steady noise comes out cleanly; sudden noise does not

Noise reduction works by learning a constant noise profile — air conditioning, a computer fan, traffic hum — and subtracting it. That's why steady background noise disappears almost completely while a door slam, a cough or a chair scrape survives untouched. Those are edits, not filter problems.

Push denoising too hard and voices develop a watery, underwater artefact as the filter removes parts of the speech along with the noise. If the room tone vanishes entirely and the gaps between words are pure digital silence, you've gone too far: a little residual hiss sounds more natural than none at all.

Fix it at the source when you can

Every processing option is damage control. Moving a mic a foot closer to the speaker improves the ratio of voice to room noise more than any filter, because you gain signal instead of removing noise. Turning off an air conditioner for a take costs nothing and removes the problem entirely.

Room tone is a tool, not a defect

Record thirty seconds of the room with nobody speaking. That clean sample of the exact noise you're fighting gives a denoiser a profile to work from, and it also lets you patch gaps in an edit so silences match the rest of the scene rather than dropping to nothing.