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About Audio Noise Reducer

Audio Noise Reducer is a free, in-browser audio tool. Reduce constant background noise (hum, hiss, fan whir, AC drone) using FFmpeg's spectral noise reduction filter (afftdn). Files are processed entirely in your browser with FFmpeg WebAssembly. The page exposes a small surface — input, controls, output — so a first-time visitor can complete the job without reading documentation.

Internally the tool runs on standard browser APIs — the same processing stack used by professional desktop pipelines, just compiled for the browser. MP3, WAV, M4A, AAC, OGG, Opus, FLAC, AIFF, and WMA files are accepted natively. 200 MB is the practical ceiling, set so the tool stays responsive on phones and older laptops.

Audio Noise Reducer is shaped for the gap between "I'll do it by hand" and "I'll script it." When the job is small enough that automating it would take longer than doing it, but annoying enough to want a focused tool — that is the situation this page is built for.

Because everything runs in the page, the tool scales the same way for one user or a million — there is no per-user backend cost. The page is static, the engine is the same JavaScript bundle for every visitor, and the work happens on the visitor's own device. That keeps the tool free and keeps it fast on the first interaction.

On limits: 200 MB per file is the ceiling. Output formats and quality settings are listed in the controls panel above, and they apply to every run.

Audio Noise Reducer sits in a small group of related tools. Useful neighbours include Audio Noise Gate, Audio Equalizer, Audio Spectrum Analyzer, and Audio Metadata Editor. They are designed to compose: the output of one is a sensible input to the next, so a multi-step task is usually a sequence of single-click operations.

Audio Noise Reducer sees the most use from sound designers prototyping cues and streamers cleaning microphone tracks, but the design is intentionally generic enough that you do not need a specialist background to get a good result. The defaults aim at the most common case so a first-time user can get the right output without changing any settings.

Once the engine finishes, `{name}-edited.{ext}` is offered as an immediate download. There is no preview gate, no email-wall, and no "register to download" intermediary — the file is yours the moment it is ready.

Audio Noise Reducer is honest about scope: it handles a single, well-defined audio editing and conversion step. Specialist edge-case work — uncommon formats, very large inputs, or pipelines that need scripting — is what dedicated desktop apps are for. This page handles the common case quickly.

Audio Noise Reducer is structured around the idea that a useful tool should be its own page. Open the page, do the work, close the tab — the page is the entire product. There is no onboarding flow because there is nothing to onboard into.

Tips from users who reach for Audio Noise Reducer regularly: process one input first to confirm the settings produce what you expect before committing to a batch; treat the page as the working surface and avoid leaving large jobs running in a backgrounded tab where the browser may throttle JavaScript; and if a particular file fails, check whether the source is intact by opening it in its native viewer — most "tool errors" are actually input errors.

Audio Noise Reducer runs as a regular web page, so there is no install step or permission grant before the first run. The page can be audited by viewing the source or by watching the developer-tools Network tab while a job runs.

If the result is not what you expected, the most common causes are easy to check. Confirm the input is under the 200 MB ceiling — files just above the cap fail silently because the engine refuses to allocate the buffer. Confirm the input is one of the supported formats. And if the page itself feels slow, try closing other heavy tabs to free up memory; the engine runs in your browser, so it competes for the same resources as everything else open.

That is the whole tool. Use Audio Noise Reducer for as long as it stays useful to you, and if it does, the catalog has many more tools built the same way. Each applies the same single-purpose discipline, so the way you used this page transfers to the next one you try.

How it works

  1. 1Open Audio Noise Reducer in your browser. The page loads quickly and the tool is ready to use the moment it becomes interactive.
  2. 2Select the MP3, WAV, M4A, AAC, OGG, Opus, FLAC, AIFF, and WMA file you want to process — drag-and-drop and the file picker both work.
  3. 3Pick any non-default settings you need. Most users leave the defaults alone for the first run and only revisit if the result needs tuning.
  4. 4Trigger processing. standard browser APIs reads your input, applies the transformation, and writes the result back into the page.
  5. 5Grab the output named `{name}-edited.{ext}` as soon as the run completes. You can also copy the result instead of downloading if the next tool in your workflow accepts pasted input.
  6. 6Re-run with different settings as often as you want. Each run produces a fresh output and the original file on disk is never modified.

Common use cases

FAQ

How does the noise reducer work?

FFmpeg's `afftdn` filter performs Fast Fourier Transform (FFT) noise reduction. It analyzes the audio in the frequency domain and attenuates frequencies that look like steady noise (constant tone, hiss, hum) while preserving frequencies that look like signal (voice, music). The result is a cleaner version of the source.

What kinds of noise does it remove?

Best for steady, continuous noise: AC hum (60/50 Hz), fluorescent buzz, fan whir, computer fans, distant traffic, cassette tape hiss, and recording-equipment self-noise. Less effective for variable noise (sudden bangs, voices in the background, dog barks) — those need a different approach.

Will it ruin the voice or music?

Aggressive noise reduction can make audio sound "underwater" or "phasey" — this is normal. For most voice recordings, the default settings remove ~80% of background noise with minimal artifacts. If you hear too much "swirling," lower the noise floor parameter.

How is this different from a noise gate?

A gate silences audio entirely when the signal is below a threshold — perfect for "silence between words." This noise reducer attenuates noise while audio is still present — perfect for "this guitar recording has fan noise the whole time." They solve different problems and are often used together.

Should I denoise before or after EQ?

Denoise first. Noise reduction works on the natural noise floor of the recording. If you EQ first, you may amplify some noise frequencies (or duck some signal frequencies) which confuses the noise reducer. The order Denoise → EQ → Normalize is the standard professional pipeline.

How big a file can I process?

Up to 200MB. Spectral noise reduction is computationally intensive — expect roughly real-time processing on a desktop, slower on mobile. WebAssembly's single-thread limit is felt most on this tool.

Why is in-browser audio processing slower than online tools?

Server-side tools use multi-threaded native FFmpeg running on dedicated CPUs with fast disks and parallel pipelines. Our engine is FFmpeg compiled to WebAssembly, which runs single-threaded inside your browser tab and has no access to native hardware acceleration. That makes browser-based jobs typically 3–8× slower than a server. The trade-off is total privacy: your audio file is never uploaded, never logged, and never stored — closing the tab erases everything from memory immediately. For most clips up to a few minutes the wait is small, and for sensitive recordings (voice memos, drafts, confidential meetings) the privacy gain is well worth it.

Is my audio uploaded?

No. Everything runs entirely inside your browser tab using FFmpeg compiled to WebAssembly. The file is read into local memory only, processed in the same tab, and the result is offered as a direct download. Nothing is transmitted to any server, no account is required, no analytics are tied to your file, and closing the tab discards every byte from memory.

How big a file can I process?

The file picker accepts audio inputs up to about 1 GB, which is well above what mainstream "free tier" online converters allow. The real ceiling is your device — everything runs inside your browser tab, which shares memory with the rest of the page. Most podcasts, songs, and voice memos sit comfortably under that limit even on a phone. If a very large lossless WAV or FLAC ever fails, trim it first or transcode to MP3 / Opus to bring the size down before re-running the tool.

Which audio formats are supported?

MP3, WAV, OGG (Vorbis and Opus), FLAC, M4A (AAC), AAC, Opus, AIFF, and WMA all decode reliably via FFmpeg WASM. Output formats depend on the specific tool — most editing tools default to MP3 (universal) or WAV (lossless) but expose a format picker so you can pick the one that fits your downstream player or DAW.

Which browsers are supported?

Recent Chrome, Edge, Firefox, Safari, and other Chromium-based browsers all work. The tool relies on WebAssembly and SharedArrayBuffer, which require the page to be served over HTTPS with the right cross-origin headers — this site is configured correctly by default. On phones the same code runs but is slower than on a desktop because mobile CPUs are weaker.

Is there a watermark, sign-up wall, or usage cap?

No. The tool is completely free, requires no account, attaches no watermark, applies no usage caps, and shows no popup ads on your output. Because the work happens on your own device, there is no per-user quota for us to enforce — your hardware and browser memory are the only limits. The download is the file you would get from running FFmpeg locally, nothing more, nothing less.

How many times per day can I use Audio Noise Reducer?

Inputs are capped at 200 MB per file, which keeps memory usage stable across phones, tablets and older laptops. You can run Audio Noise Reducer as often as you need; every run produces a full-quality result.

How accessible is the Audio Noise Reducer interface?

Audio Noise Reducer uses native HTML controls wherever possible, which means keyboard navigation, focus rings, and screen-reader labels work the way the platform expects. The drop zone accepts files via the keyboard-accessible file picker as well as drag-and-drop, and result downloads use standard browser download flows. If you spot an accessibility gap, Favtoo treats it as a bug worth fixing.

Is it safe to use Audio Noise Reducer on confidential files?

Your file is processed inside your browser by standard browser APIs. The engine reads the file's bytes from your tab's memory, computes the result, and writes the result back into the tab. You can confirm what the page does by opening developer tools and watching the Network tab during a run — the requests you see are for the tool's static assets only.

Is Audio Noise Reducer mobile-friendly?

Audio Noise Reducer runs in any modern mobile browser — Safari, Chrome, Firefox and the in-app browsers in most messaging apps all support the underlying APIs. Performance depends on the device: a recent phone handles typical inputs nearly as fast as a laptop, while older devices may take a few seconds longer near the 200 MB ceiling. The interface lays out cleanly on small screens, so you do not need to pinch-zoom to see the controls.

How do I know I am using the latest version of Audio Noise Reducer?

Audio Noise Reducer is updated whenever the underlying engine releases an improvement or a bug fix. Because the tool is delivered as a static page, every visit fetches the latest version automatically — there is no "version" to manage on your end. If a particular release ever changes default behaviour, the change is documented on Favtoo's changelog so you can confirm what shifted.

Do I need a specific browser to use Audio Noise Reducer?

Audio Noise Reducer works in any modern browser released in the last few years — Chrome, Edge, Firefox, Safari, Brave, Arc and the major Chromium derivatives are all supported. The underlying engine relies on widely-supported web APIs, so there is nothing exotic to install. If you are on a very old browser version and the tool fails to load, updating to the latest release of your preferred browser is the only fix needed.

Does Favtoo keep a copy of files I process with Audio Noise Reducer?

Favtoo keeps no copy of your file because Favtoo never receives your file. Audio Noise Reducer runs entirely in your browser, the input is held only in your tab's memory, and closing the tab discards it. There is no opt-in cloud history, no "recent jobs" panel synced to an account, and no server-side retention to configure — the architecture simply has nowhere for your file to be stored.

Is there a programmatic version of Audio Noise Reducer?

Audio Noise Reducer is a browser-only tool by design and does not expose a hosted API. The reason is the same as the privacy story: there is no Favtoo backend doing the work, so there is no service to call. If you need to script the same transformation, the underlying engine (standard browser APIs) is open-source and can be used directly from your own code.

Why does Audio Noise Reducer feel slow on large inputs?

Most jobs finish in seconds. Speed scales with input size and with how many CPU cycles your browser tab has available — the engine runs in your browser, so it shares resources with whatever else you have open. For inputs near the 200 MB ceiling, expect anywhere from a few seconds to roughly a minute on a typical laptop. Closing other heavy tabs noticeably speeds things up.

Audio Recorder

Record from your microphone directly in the browser. Pick quality (high, medium, low), toggle echo cancellation, noise suppression and auto-gain, then save to WebM/Opus or M4A/AAC. Audio is captured locally — nothing is uploaded.

Text to Speech

Type or paste text, pick a system voice, and listen instantly. Adjust speaking rate (0.5×–2×), pitch, and volume in real time. Uses your browser's built-in Web Speech API — no cloud TTS, no API keys, no costs.

Tone Generator

Generate a pure tone at any frequency from 20 Hz to 20 kHz. Pick a sine, square, triangle, or sawtooth waveform, choose duration, amplitude, and mono/stereo. Exports a 16-bit PCM WAV file at 44.1 kHz with built-in click-preventing fades.

Silence Generator

Generate a perfectly silent WAV file of any length from 1 second up to 1 hour. Pick mono or stereo, get a 16-bit PCM WAV at 44.1 kHz. Useful as padding between clips, intro silence, leader audio for video timing, or test material.

White Noise Generator

Generate white, pink, or brown noise as a 16-bit PCM WAV file. Pick noise type, duration up to 1 hour, amplitude, and mono/stereo. Useful for sleep, focus, masking distractions, audio testing, and as a backing layer for ambient music.

Metronome

A precise browser-based metronome powered by the Web Audio API. Set BPM from 30 to 300, choose a time signature, accent the first beat, and use tap-tempo to sync. Click timing is sample-accurate using lookahead scheduling — much steadier than typical JavaScript setInterval beats.

Audio Trimmer

Trim any audio file to a precise start and end time. Outputs a lossless stream-copy by default (no quality loss, very fast) or re-encodes to MP3, WAV, OGG, or M4A. Files are processed entirely in your browser with FFmpeg WebAssembly.

Audio Splitter

Split a long audio file into N equal-length parts and download them as a ZIP. Each part is named sequentially. Great for chapterizing audiobooks, podcasts, or long DJ mixes. Runs entirely in your browser with FFmpeg WebAssembly.

View all Audio Tools