Upload a recording and get the hum and hiss pulled out — electrical buzz, mic self-noise and steady background static removed while the voice stays natural. Free, no account.
The cleaned file is the free file. No watermark, no trial length, no account — files up to 45 minutes. A pass adds loudness levelling and a heavier repair pass for rough recordings.
By ShinobiTools Team · Last updated: July 2026
Most of what lands in CleanGrab for hum-and-hiss cleanup is small. Looking at the sizes of the 379 files we logged sitewide over the 31 days to 21 August, the single biggest cluster — 150 of them — sat between 32 and 64 KB: short voice memos and clips, exactly the kind of recording where a mic's own hiss or a bad ground hum is loudest relative to the voice. Two more clusters, 38 files between 4 and 8 MB and 33 between 16 and 32 MB, cover longer interviews and lectures where the same steady buzz just runs on for longer. The pattern holds either way: hum and hiss don't scale with file length, they're constant in the recording, so a short memo and a long lecture can have exactly the same buzz running underneath. None of that is a guess about your specific file — it's the shape of what actually came through our own server logs in that stretch, not a marketing estimate.
Hum is the low, steady buzz from mains electricity or a bad cable ground (50/60 Hz and its overtones). Hiss is the higher, airier background static from a cheap microphone, a room's own noise floor, or a badly-gained recording. Both sit constantly under the voice, and our own model is built to recognise and remove exactly that kind of steady background noise, not just the voice's own transients.
On a recording where hum and hiss are the main issue, CleanGrab typically gets you most of the way there in one pass. Heavy room echo and reverb are a harder, separate problem: CleanGrab reduces light echo, but it will not fully erase a very reverberant room. We'd rather say that plainly than promise something the tool can't do.
CleanGrab is tuned for voice and speech — podcasts, interviews, calls, voice memos, lectures. On music or other non-speech audio the result can be poor, and the tool will tell you when it couldn't detect clear speech instead of handing you a mangled file.
Dealing with rustling instead of a steady hum? See removing fabric rustling noise. If the room itself is ringing rather than buzzing, the room echo page is the better fit, roaring wind on an outdoor recording is a harder, different problem covered on the wind noise page, and for the full range of background noise there's the background noise remover.
Hum is a low, steady electrical buzz (mains frequency and its overtones); hiss is higher-pitched background static, usually from a microphone's own noise floor. CleanGrab removes both kinds of steady background noise.
Yes — fans, air conditioning, traffic and keyboard clatter are removed alongside hum and hiss, as long as the voice itself is clear.
Yes — start on Balanced, then go Strong for stubborn hum or hiss, or Gentle if the voice starts to sound over-processed.
Heavy room echo and reverb are a harder, separate problem: CleanGrab reduces light echo, but it will not fully erase a very reverberant room. We'd rather say that plainly than promise something the tool can't do.
Yes — CCTV and doorbell cameras often pick up a steady mains hum from nearby electronics; upload the clip and CleanGrab strips it out the same way it handles hum from any other recording.
No. Your upload is deleted the moment it's processed and the cleaned file is wiped from the server within 45 minutes. Nothing is stored, shared or used to train anything — see privacy.