♪ E A D G B E ◅ ┃ ▻ · tune to the green centre · cents
Free Online Guitar Tuner & Instrument Tuner_
A chromatic tuner that listens
This free online guitar tuner uses your device's microphone and the Web Audio API to detect the pitch you play in real time. Pluck a string and the gauge shows the note name and how many cents sharp or flat you are — tune until the needle locks into the green centre. Pick a tuning preset for guitar, bass, ukulele, violin or cello (plus drop D), or use chromatic mode for any instrument. You can shift the A4 reference for alternate concert pitch, and tap a string to hear its reference tone. Everything runs locally — no audio is recorded or uploaded.
How to tune
FAQ & about the tuner
FAQ — Online Guitar & Instrument Tuner
How does the online guitar tuner work?
Press Start and allow microphone access, then play a single note. The tuner analyses the sound with the Web Audio API and an autocorrelation pitch-detection algorithm, showing the detected note and how many cents sharp or flat you are. Tune until the needle sits in the green centre.
What is standard guitar tuning?
Standard six-string guitar tuning is E2 A2 D3 G3 B3 E4, from the thick low string to the thin high string. The Guitar preset snaps to the nearest of those six strings; choose Chromatic to tune to any note.
Which instruments can I tune?
Presets for guitar (standard and drop D), bass, ukulele, violin and cello, plus a chromatic mode that tunes to any note — so it works for almost any instrument that plays a clear sustained pitch.
Is my audio recorded or uploaded?
No. All pitch detection happens locally in your browser. The microphone stream is analysed in real time and never recorded, stored or sent to any server.
Can I change the A4 reference pitch?
Yes — it defaults to A4 = 440 Hz but you can set it from 430 to 450 Hz, useful for playing along with instruments tuned to a different concert pitch such as 432 Hz or 442 Hz.
Is it free?
Completely free, no account, no ads. It runs entirely in your browser. It's one of the free tools at jasperbernaers.com.