Condensed cross-post of the original KeyboardTester.click guide: What Note Am I Singing? Find It by Humming (No App).
A melody is stuck in your head, or a choir director just asked for your range, and you want to know whether the note you are matching is really a G. You do not need an app, and you do not need someone with perfect pitch next to you. Any laptop or phone browser with a working microphone can name the note you are humming in seconds.
The fast answer: open the free live note check, allow the microphone, and hum a steady note on "ah" or a closed-mouth "mmm" for two to three seconds. The screen shows the note name, the octave, the frequency in Hz, and how many cents sharp or flat you are.
How it works (and why humming beats singing)
The detection method is autocorrelation, the same family of algorithms most tuner apps use: the browser compares your waveform against delayed copies of itself and finds the period at which it best matches. It runs entirely on your device through the Web Audio API - nothing is uploaded.
That approach is also why humming gives a steadier reading than singing lyrics: every consonant and vowel change disturbs the waveform the detector is tracking. A sustained "ah" or a gentle closed-mouth "mmm" produces a clean, periodic signal that locks in almost immediately.
Technique checklist:
- Start from your speaking voice: say "ah", then let it settle into a hum at the same comfortable height.
- Stay roughly 15-30 cm from the microphone.
- Keep airflow slow and even - think of a long, lazy sigh on one note.
- Avoid slides, scoops, and vocal fry; land on the note directly.
- Pick the quietest room available. If you are unsure how noisy it is, measure it with a browser decibel meter first.
Reading the result: notes, octaves, Hz, and cents
Middle C is C4, and the A above it, A4, is the international tuning reference: ISO 16 fixes A4 at exactly 440 Hz. A full 88-key piano spans A0 at 27.5 Hz up to C8 at 4186 Hz; most voices live in a narrow band inside that.
Cents describe how far you are from the nearest note. One semitone is divided into 100 cents (an octave is 1200), so a reading of +20 means you are 20% of the way up toward the next note - sharp. Practical guidance for held notes:
| Cents from the note | How it reads |
|---|---|
| Within ±5 | On the note (professional-level target) |
| ±5 to ±15 | Usually heard as in tune |
| ±15 to ±30 | Audibly sharp or flat on sustained notes |
| Beyond ±30 | Closer to the neighboring semitone - re-anchor |
Why the reading jumps (and the octave-error fix)
A jumping reading almost always has a physical explanation:
- Vibrato - if your voice naturally oscillates, the detector faithfully reports a pitch swinging a few dozen cents several times per second. That is your voice, not a bug.
- Browser voice-call processing - automatic gain control, noise suppression, and echo cancellation are standard, documented microphone constraints. They are designed for speech calls and can pump levels or briefly suppress parts of a sustained tone.
- Octave errors - you hum a low note and the display shows the right letter one octave up. Low voices often produce a second harmonic stronger than the fundamental, and an autocorrelation detector can briefly latch onto it. Two cures: hum louder so the fundamental dominates, and bring the mic closer for more low-end energy. The Hz value confirms which octave you actually produced.
If the reader shows nothing at all, verify the input first with a quick microphone test.
Two things you can do with a steady reading
Practice singing in tune. Play a reference note, hum it back, read the cents value, correct once, hold, and compare. If your average error shrinks week over week, you are objectively singing more in tune. (Honest scope: cents measure pitch on one held note - not tone, rhythm, or diction.)
Map your rough vocal range. Slide down to the lowest note you can hold cleanly for two seconds, then up to the highest without straining, and note both (for example, G2 to E4). Anchor point: conversational speech averages around 120 Hz for men (near B2) and 210 Hz for women (near G#3).
One honest limitation: a browser reading through a consumer mic is excellent for naming notes and practicing, but it is monophonic (one voice at a time) and not a calibrated instrument-grade tuner.
Try it yourself: live note and pitch check - and the full guide with the what-you-see table, the practice loop, and the vocal-range walkthrough lives here: What Note Am I Singing? Find It by Humming (No App).
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