Online Pitch Detector & Note Finder
Need to know what note is this? Play, sing or hum one clear sound into your microphone. This pitch detector identifies the closest note and octave, measures its frequency in Hz, and shows whether it is sharp or flat in cents. It runs in your browser while detection is active, with no account or audio upload.
What note is this? Start with one clear sound
Press Start detection, allow microphone access, then sing, hum or play one note at a time. The display names the closest chromatic note such as A4 or C♯3. The number is the octave, which distinguishes notes with the same letter name at different pitches.
For a stable result, hold the note for a second in a quiet room. A guitar string, tuning fork, whistle, violin note or sustained vowel works well. Chords, piano clusters, backing tracks and several people singing together contain multiple pitches, so a monophonic note detector cannot reliably name every note at once.
Read frequency, cents and the tuning meter
The frequency value is the measured number of waveform cycles per second. The detector maps it to the nearest equal-temperament note using A4 = 440 Hz. A steady 440 Hz sound therefore reads as A4.
The cents value shows the distance from that note. Negative cents are flat, positive cents are sharp, and 100 cents equal one semitone. The centre of the small horizontal scale is the target pitch; readings within five cents show In tune. Let a note settle before adjusting your instrument or voice.
Use it as a pitch checker for voice or instruments
This tool is a general pitch checker, not an instrument-specific tuner. It looks for one fundamental frequency between 55 and 1,200 Hz, covering many singing notes and instrument pitches. Notes outside that range, including the lowest strings of a standard bass guitar, are not supported.
Use the tone generator to hear a reference pitch before you sing or tune. If the detector does not react, confirm your input works with the microphone test. The broader audio tools also include speaker and headphone checks.
Why a note detector can be wrong
Pitch detection estimates the fundamental frequency in the microphone signal. Background noise, an abrupt note attack, strong vibrato, a distant microphone and prominent harmonics can make the reading move or select the wrong octave. A sustained, isolated sound is easier to measure than speech or a full song.
This page uses a YIN-style difference function with 2,048-sample frames, or 4,096 samples at input rates above 48 kHz. It smooths nearby results and keeps the last detected note visible until another valid note arrives. The status distinguishes a held result from a current measurement, and the history chart leaves gaps when no clear pitch is found. It is useful for practice and quick identification, but it is not a calibrated measurement instrument or a chord recogniser.
Frequently asked questions
What note am I singing or playing?
Start detection and hold one steady sound near the microphone. The large label shows the nearest note and octave, while the Hz value shows the measured frequency.
If the note jumps, reduce background noise and sustain the sound a little longer. The tool is built for one pitch at a time, not a chord or full recording.
Is a pitch detector the same as a note finder or pitch checker?
They describe closely related jobs. A note finder identifies the nearest note, while a pitch checker also shows whether the sound is sharp or flat. This page does both, along with the octave and frequency in Hz.
An instrument-specific tuner usually expects a fixed set of target strings or notes. This detector can identify a single pitch anywhere in its 55–1,200 Hz range.
Why does the reading show the wrong octave?
A strong harmonic can be louder than the fundamental, especially on some voices and instruments. Room noise and overlapping notes can create the same problem.
Hold one sustained note, move a little closer to the microphone and mute other strings or sound sources. Check that the intended note falls within the supported range. These steps can help, but cannot eliminate every octave error.
Can I tune a guitar, violin or another instrument with this?
Yes, when you play one string or one note at a time. Watch the note name first, then use the cents meter to bring the pitch closer to the centre.
For a chord, tune each string separately. Several simultaneous notes make the fundamental ambiguous, so the result is not dependable for a full chord.
Does this page record or upload my microphone audio?
No. Microphone samples are analysed in the current browser tab while detection is running. Automatic history stores measured frequencies and timestamps on this browser, not an audio recording, and does not upload them.
Stop detection releases the microphone. You can also revoke microphone permission through the browser's site controls.
How do I save and reopen my pitch history?
History saves automatically while you detect notes, with periodic updates and a final save when you stop. Select a session below the chart to review it; select it again to return to the live chart. Hover over the trace, or focus it and use the arrow keys, to inspect a note's frequency, cents and time.
The latest ten sessions stay in this browser, with up to 1,500 measurements per session (roughly the latest two and a half minutes). They do not sync between devices. Delete removes a saved session, and clearing browser site data also removes saved history. If browser storage is blocked or full, the page reports that auto-save is unavailable. An abrupt browser crash may lose the most recent unsaved seconds.
Can a pitch detector tell me the key of a song?
No. This detector identifies a single current pitch, not the musical key of a complete song. A song usually contains chords, percussion and several instruments or voices at the same time.
Use it to identify one isolated note or to check your intonation. Key detection needs a separate analysis of the song's notes and harmonic context.