Online guitar tuner
Allow microphone access, play one string at a time and turn the tuning peg until the needle is centred. Also works for bass, ukulele and other instruments.
Voluntary support · Thank-you gift: our checklist PDF · Secure checkout via Digistore24 (Apple Pay, Google Pay, PayPal, card)
🔒 Camera, microphone and screen data are processed only in your browser – nothing is uploaded or stored by us.
How to use it
- Click “Start tuner” and allow microphone access.
- Play a single string; the display shows the note and how many cents it is off.
- Tighten the string if it is too low, loosen it if it is too high – until “In tune” appears.
Last checked: October 2026. Found a mistake? Use the form below – we fix confirmed errors and update the date.
Frequently asked questions
What is standard guitar tuning?
From the thickest to the thinnest string: E2, A2, D3, G3, B3, E4 (82.4 Hz to 329.6 Hz).
Does it work on my phone?
Yes, in current mobile browsers. Hold the phone close to the guitar and avoid background noise.
What are cents?
A cent is 1/100 of a semitone. Within ±5 cents most people hear the note as in tune.