Online Guitar Tuner
Tune your guitar with your microphone. This free online guitar tuner hears the string you play, finds the closest note in your chosen tuning, and shows exactly how far off you are in cents — with reference tones you can play by ear.
How to Tune Your Guitar in Three Steps
Start the Tuner
Press Start and allow microphone access when your browser asks. All processing happens locally — your audio never leaves the device.
Play an Open String
Pluck one string and let it ring. The tuner names the string it hears and the needle shows whether you are flat (left) or sharp (right), in cents.
Adjust Until Green
Turn the tuning peg as the needle guides you — tighten to raise pitch, loosen to lower it — until the needle parks in the green center zone and the note glows.
Supported Guitar Tunings
The Tuning dropdown ships with 19 presets, grouped the way players actually reach for them. Every preset relabels the string buttons and retunes the reference tones to match, and chromatic mode covers any note no preset lists.
Standard Tuning
- Standard (E A D G B e) — the tuning that virtually all songs, tabs and chord charts assume. Start here if you are new.
Drop & Power Tunings
- Drop D — lower the sixth string one step for one-finger power chords; a rock and metal staple.
- Double Drop D — both E strings down to D, the folk and Neil Young favourite.
- DADGAD (D Modal) — the droney folk and Celtic tuning; sus chords ring everywhere.
- Drop C, Drop B, Drop A — progressively heavier: the whole guitar drops, then the sixth string drops another step.
Open Tunings
- Open E, Open G, Open D — strum the open strings and a major chord rings out; slide-guitar favourites.
- Open A, Open C — brighter major voicings for slide and fingerstyle work.
- Open Em, Open Dm — the minor counterparts: open strings ring a minor chord.
Shifted & Alternate Tunings
- Half Step Down (Eb) — matches a shelf of classic-rock records and eases vocal keys.
- Whole Step Down (D) — lower tension, deeper voice; common in modern rock.
- Plus 1, Plus 2 — everything up a semitone or a tone for brighter keys and tighter tension.
- All 4th (E A D G C F) — symmetric fourths, loved by jazz and experimental players.
Why This Online Guitar Tuner Reads in Cents
A semitone is 100 cents, and the distance between two adjacent guitar strings is 400–700 cents — so even 20 cents of error still sounds like the right note. But played together with other instruments, errors as small as 10 cents start to beat and sound sour. That is why this tuner reads out cents: the green zone marks ±5 cents, which is tighter than most ears can detect and tighter than most clip-on tuners promise.
Under the hood it runs the same YIN pitch-detection algorithm as our vocal range test, tuned to the guitar's open-string range (D2 to E4 across the supported tunings) with temporal smoothing so the needle stays readable while the note rings.
Frequently Asked Questions
How do I tune my guitar with this online tuner?
Press Start and allow microphone access, then play any open string and hold it steady. The tuner automatically identifies the closest string, shows how many cents you are off, and tells you whether to tighten or loosen the string. Adjust the peg until the needle sits in the green zone.
Is this guitar tuner accurate?
The tuner uses the same YIN pitch-detection algorithm as our vocal range test, measuring pitch to within a few cents on a clean signal. For best results tune in a quiet room, mute the other strings with your picking hand, and let the note settle before adjusting.
Does the tuner support Drop D and other alternate tunings?
Yes — 19 presets grouped by family: drop and power tunings (Drop D, Double Drop D, DADGAD, Drop C, Drop B, Drop A), open tunings (Open E, G, D, Dm, C, A and Em), shifted standards (half step down, whole step down, Plus 1, Plus 2) and All 4th. Reference tones retune with your selection — and if your target note isn't in any preset, chromatic mode tunes to any of the twelve notes.
What is chromatic mode?
Auto mode listens for the six strings of the selected tuning. Chromatic mode instead shows the nearest of all twelve notes with the same cents meter — useful for songs between standard tunings, intonation checks at any fret, or instruments beyond guitar.
Is my microphone audio uploaded anywhere?
No. All pitch analysis runs locally in your browser with the Web Audio API. Nothing is recorded, stored, or sent to a server.
More Free Music Tools
Practice on the virtual guitar, play the online piano, find your voice type with the vocal range test, or watch any note you sing or play on thereal-time pitch detector.