Is this online tuner free?

Yes. The tuner is completely free, needs no account, and runs entirely in your browser.

Does the tuner send my audio anywhere?

No. Your microphone audio is analysed locally in the browser using the Web Audio API. Nothing is recorded and nothing is uploaded.

Why does the tuner need microphone permission?

A tuner has to hear the note you play, so the browser asks for microphone access. You can revoke it at any time and the page will stop listening immediately.

Can I use it without a microphone?

Yes — use the reference tones section to play a note and tune by ear, or use chromatic mode to identify a note you already hear.

Which tunings are included?

Standard guitar (E A D G B E), 4-string bass (E A D G), ukulele (G C E A) and violin (G D A E), plus a fully chromatic mode for any instrument.

Online Tuner — Free Chromatic, Guitar, Bass & Ukulele Tuner

Play one string at a time and watch the needle. When the note name matches the string you are tuning and the needle sits in the green centre zone, that string is in tune. The number under the note is the deviation in cents — one cent is one hundredth of a semitone, so anything inside ±5 cents is inaudibly close to perfect.

Standard tunings

Instrument	Strings (low to high)	A4 =
Guitar	E2 · A2 · D3 · G3 · B3 · E4	440 Hz
Bass (4-string)	E1 · A1 · D2 · G2	440 Hz
Ukulele	G4 · C4 · E4 · A4 (re-entrant)	440 Hz
Violin	G3 · D4 · A4 · E5	440 Hz

How the tuner works

The page listens through your microphone, measures the fundamental frequency of the note using the YIN pitch-detection algorithm, and converts it to the nearest note on the equal-tempered scale. YIN is used instead of simple autocorrelation because it does not jump a whole octave on instruments with strong overtones, which is the most common failure mode of a naive tuner.

Microphone audio never leaves your device. It is analysed frame by frame in the Web Audio API and discarded immediately — there is no recording, no upload and no account.

Frequently Asked Questions

Why is the tuner not picking up my note?

Play one string at a time, close to the microphone, and let the note ring. Background noise, a very quiet instrument or a room with heavy reverb can all hide the fundamental. Use clean (not overdriven) tone — distortion adds overtones that make pitch detection harder.

Why does the note name show a different string than the one I am playing?

The big note name is what the tuner actually hears. If it disagrees with the string you plucked, you are either too far out of tune for that string or you are on a different string — turn the peg in the direction of the cents readout until the note name snaps to the string you want.

What does the cents number mean?

Cents measure how far you are from the target pitch. 100 cents is one semitone. A positive number means sharp (tune down), a negative number means flat (tune up). Under ±5 cents is in tune.

Does it work for other instruments?

Yes. Choose Chromatic and the tuner will show the nearest note from the full 12-note scale for any instrument — banjo, mandolin, cello, a voice, or a hardware synth.

Does it need an internet connection?

Only to load the page. Once loaded, tuning and reference tones run entirely offline in your browser.

Related Tools

Ready to play in time? Use the online metronome.