A Webstarted Toolbox widget · macOS & Windows

A white noise generator in your menu bar — no files, no streaming.

White, pink or brown noise, synthesized live on your machine with volume and a tone filter that takes it from a bright hiss to something soft and distant. Nothing to download, nothing to stream, no loop you can hear — and it works with the Wi-Fi off.

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Free · No account · 100% offline · Installs from the Toolbox catalog
3 noise colorsWhite · pink · brown
No audio filesNothing to download
Never repeatsGenerated, not looped
OfflineNo stream, no ads, no buffering
How it works

Pick a color, set the volume, shape the tone. That’s the whole interface.

Open the popover from your menu bar (macOS) or system tray (Windows), pick white, pink or brown, and press play. Each option carries a one-line description of what it actually sounds like, so choosing isn’t a guess. Two sliders do the rest: volume, on a quadratic curve so the quiet end has real resolution, and tone, a low-pass filter that runs from 200 Hz to 18 kHz.

The audio lives on your system’s audio thread, not on a JavaScript timer, so it keeps going while you work in another app instead of being tied to a visible window. Starting and stopping are faded over a quarter of a second — no click in your headphones. And if you want it permanently on screen, the ↗ button pops the widget into its own window.

  • White, pink and brown, each with a plain-language description
  • Volume on a quadratic curve · tone as an exponential low-pass, 200 Hz → 18 kHz
  • Runs on the audio thread — not gated by the popover being open
  • 0.25 s fade in and out, so play and stop never click
  • Window mode (↗) to leave it running visibly
Why synthesized

No rain samples — and that turns out to be the feature.

Let’s be straight about what this is not: there are no recordings in here. No rain, no café, no forest, no fireplace. A widget in this catalog ships as code, not as media, so an audio library was never on the table — and a loop long enough to not be noticeable would weigh megabytes anyway.

What you get instead is noise computed sample by sample while it plays, and that has three properties a sample pack can’t match: it weighs nothing, it needs no connection, and it never repeats. That last one matters more than it sounds — once you’ve noticed the seam in a ten-minute loop, you keep hearing it, and the thing meant to help you concentrate becomes the thing you’re listening for.

If you specifically want rain on your headphones, use a streaming app. If you want something that masks an open-plan office, starts instantly and never phones home, this is the trade you want.

  • Zero audio assets — nothing downloaded, nothing cached
  • No seam, no loop point, no “here it comes again”
  • No account, no ads, no tracking of what you listen to
  • Honest limit: no rain / café / forest recordings
This widgetStreaming apps
Works offline
Audible loopNoneCommon
Ads / accountNoneOften
Download size~0MBs
White / pink / brownVaries
Rain / café samples
Sleep timer
White, pink, brown

Three colors, and what each one is actually good for.

White noise spreads its energy evenly across the spectrum. It is the brightest of the three and the best at masking speech, which is why it is the one that works in a shared room or an open-plan office where the problem is a conversation two desks away.

Pink noise loses energy as frequency rises. Most people find it the least fatiguing over hours — it is the default choice for long stretches of deep work. Brown noise falls off faster still: low, round, closer to a rumble than a hiss, and with the tone slider pulled down it lands somewhere near distant rain. It is the gentlest of the three if bright sounds bother you.

The widget’s tests don’t just check that audio comes out — they verify the color of the noise by measuring its roughness, and that the output never clips. Which is a long way of saying: the pink is really pink.

  • White — masking nearby voices in a shared space
  • Pink — long focus blocks without ear fatigue
  • Brown — low and soft; with tone down, near distant rain
  • Verified by tests for noise color and against clipping
Part of Webstarted Toolbox

Installed from the catalog, in one click.

Focus Sounds isn’t bundled into the app — it’s a widget in the Webstarted Toolbox catalog. Download Toolbox, open the catalog tab (🧰), press the “+” next to Focus Sounds, and it lands in your Focus tab, right beside Pomodoro. No reinstall, no app update:

FAQ

Questions, answered.

Are these recordings of rain, a café or a forest?

No, and it is worth being clear about it: there are no audio files in this widget at all. It synthesizes noise mathematically as it plays — white, pink and brown. If what you want is a rain or coffee-shop recording, this is not that tool. What comes closest is brown noise with the tone turned down, which most people hear as something like distant rain.

What is the difference between white, pink and brown noise?

It is how the energy is spread across frequencies. White is flat and bright — a “shhh” that is good at masking nearby voices. Pink drops off as frequency rises, which is why most people describe it as the most natural of the three. Brown drops off faster still: deep and enveloping, closer to a rumble. The widget describes each one right next to the button so you are not guessing.

What does the tone slider do?

It is a low-pass filter, mapped exponentially from 200 Hz up to 18 kHz — exponentially because what your ear registers is octaves, not a linear count of hertz. Turn it all the way up and you hear the raw noise; turn it down and the highs get filtered away, which takes the same source from a bright hiss to something soft and distant. Volume is on its own quadratic curve so the quiet end has usable resolution instead of jumping from silent to loud.

Does it need an internet connection?

No. Nothing is downloaded and nothing is streamed — the audio is generated on your machine, so it works on a plane, on a train, or on a network that blocks streaming. It also means no buffering and no ad interrupting your focus block 40 minutes in.

Does the sound stop when I close the popover?

The audio runs on your system’s audio thread rather than on a JavaScript timer, so it is not gated by the popover being visible — cutting the sound the moment you look away would be the opposite of what a focus sound is for. If your setup does stop it, open the widget in its own window with the ↗ button and leave it playing while you work. Play and stop are faded over a quarter of a second so you never get a click in your headphones.

Is there a sleep timer?

Not in this widget — it plays until you stop it. If you want a bounded session, run it next to Pomodoro or Quick Timer in the same app: the timer handles the “when”, this handles the “what it sounds like”.

Is it free?

Yes. Webstarted Toolbox is free and needs no account, and Focus Sounds is a free widget in its catalog — you install it in one click from inside the app.

Get Webstarted Toolbox

Free to use. Download the app, then add Focus Sounds from the catalog in one click. macOS 12+ and Windows 10+.

Free beta · macOS · Windows (x64) · Signed & notarized · No account required
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