How to Tune a Guitar Online (Free Browser Tuner)
Updated 2026-06-21
To tune a guitar online, open a chromatic tuner in your browser, allow microphone access, then play one string at a time and adjust the tuning peg until the detected note matches the target and the cents reading sits at zero. Standard guitar tuning, from the thickest (lowest) string to the thinnest, is E2, A2, D3, G3, B3, E4.
Tune your guitar string by string
- Open the Metronome & Instrument Tuner and grant microphone permission when prompted.
- Pluck a single string and let it ring — the tuner shows the nearest note name plus how many cents sharp or flat you are.
- If the note reads lower than your target (for example D3 when you want E2's neighbor), turn the peg to raise the pitch; if it reads higher, lower it.
- Aim for 0 cents. Anything within about plus or minus 5 cents will sound in tune to most ears.
- Repeat for all six strings, then re-check the first string — adjusting one string's tension can slightly pull the others.
A worked example: you play the low string and see D#2, +30 cents. That means you're close to E but flat. Tighten the peg slowly until the name flips to E2 and the cents needle settles on zero.
Beyond standard: drop tunings and other instruments
The same process covers alternate tunings — just change your target notes:
- Drop D: lower the 6th string from E2 to D2, leave the rest standard.
- DADGAD: tune to D2, A2, D3, G3, A3, D4.
Because this is a chromatic tuner, it names whatever pitch it hears, so it works for any tuning without a special mode. It also handles other instruments: bass (E1, A1, D2, G2), ukulele (G4, C4, E4, A4), and bowed strings like violin (G3, D4, A4, E5) and cello. Use the built-in reference tones to hear the target pitch and tune by ear, or to check the microphone reading.
Set your reference pitch (A4 = 440, 432, or 442)
Most modern tuning uses A4 = 440 Hz. If you play in an orchestra or with a piano set to a different standard, adjust the A4 value — common alternatives are 442 Hz (many orchestras) and 432 Hz. Changing A4 shifts every target note accordingly, so set it before you start tuning.
Common pitfalls
- Noisy rooms confuse pitch detection. Tune somewhere quiet and play one string at a time.
- Old strings drift and read inconsistently — if a string won't hold a steady note, it may need replacing.
- Tune up to the note, not down. Approaching from below keeps the string under steady tension and holds pitch longer.
Everything runs locally in your browser — your microphone audio is processed on your device and never uploaded. There's no app to install and no signup.
Ready to get in tune? Open the Metronome & Instrument Tuner and start with your low E.