Setup
Ear Tuner
Tap a string to hear its pitch
Tap a string above to hear it
Tune the guitar to itself
- String 6fret 5String 5 open (A2)
- String 5fret 5String 4 open (D3)
- String 4fret 5String 3 open (G3)
- String 3fret 4String 2 open (B3)
- String 2fret 5String 1 open (E4)
No microphone needed. Match each string to its tone by ear, then check the others against it. Useful when the mic is poor, the room is noisy, or you would rather trust your ear.
Tuning Reference
Target frequencies at A4 = 440 Hz
Reference tones load the first time you tap a string.
About This Online Guitar Tuner
Guitar Tool Hub's free online guitar tuner has two independent modes, and neither is a fallback for the other. The microphone tuner uses your device's mic to detect the pitch you're playing in real time, shows the closest string match, and displays cents deviation on a visual needle so you can see exactly how sharp or flat you are — and you can lock it to one string when a string is so far out it reads as the wrong note. The ear tuner plays a precise reference tone for each string so you can tune by listening — no microphone needed, which is what you want on a laptop with a poor built-in mic, in a noisy room, or if you simply trust your ear. Tapping a string plays its tone at any time. Reference pitch is adjustable from 415 to 466 Hz for tuning to a recording or a piano that isn't at A440. Supports standard tuning plus 26 alternate tunings across drop, open, modal, step, and alternate categories. All pitch detection runs on your device — no audio is recorded or uploaded.
- 01Microphone tuner with real-time pitch detection
- 02Cents deviation display with visual needle
- 03Manual string lock for badly out-of-tune strings
- 04Adjustable reference pitch (A4 415–466 Hz)
- 05Ear tuner with reference tones for each string
- 06Fret-matching reference for tuning the guitar to itself
- 07Auto-play mode cycles through all strings
- 08Standard tuning + 26 alternate tunings
- 09Drop tunings: Drop D, Double Drop D, Drop C#, Drop C, Drop B, Drop A
- 10Modal tunings: D Modal (DADGAD), G Modal
- 11Open tunings: Open C, Open E, Open F, Open G, Open A, Open A 2, Open Am, Open Em, Open D, Open Dm
- 12Step tunings: Half Step Down, Full Step Down, +1 Semitone, +2 Semitones
- 13Alternate tunings: Double Daddy, All 4ths, NST, Ostrich
- 14Audio never leaves your device
- 15Works on desktop and mobile browsers
- 16Free — no app download needed
Frequently Asked Questions
Press Start mic and allow microphone access when your browser asks. Play one string at a time — the tuner detects the pitch, shows which string it matches, and the needle shows how many cents sharp or flat you are. Turn the tuning peg until the needle sits in the green centre band. No app or download is needed, and it works on a phone as well as a computer.
Yes — this one. It uses your device microphone for real-time pitch detection, free and with no account or download, and shows the detected note, the target frequency in hertz, and the deviation in cents. If you would rather not use a microphone, the same page plays a reference tone for every string so you can tune by ear.
This tuner analyses the audio on your own device using the browser's Web Audio API. Nothing is recorded, stored, or uploaded, and the microphone is released as soon as you press Stop mic or leave the page. You can revoke access at any time from the icon in your browser's address bar.
A string that is more than about half a semitone off is genuinely closer to a different note, so automatic detection names that one instead. Tap that string in the Strings row to lock the tuner to it — the needle will then measure against the string you meant, however far out it is. Tap it again to return to automatic detection.
Yes. The reference pitch control sets A4 anywhere from 415 Hz to 466 Hz, and every string's target frequency moves with it. Use it to match a recording, an older piano, or a band tuned to 432 Hz. Your choice is remembered on your device.
Use the microphone tuner to let your browser detect your guitar's pitch automatically and show cents deviation in real time, or choose the ear tuner to hear reference tones for each string and tune by ear. Both are free and need no download.
Standard tuning (E A D G B E) plus 26 alternate tunings: Drop D, Double Drop D, Drop C#, Drop C, Drop B, Drop A, D Modal (DADGAD), G Modal, Open C, Open E, Open F, Open G, Open A, Open A 2, Open Am, Open Em, Open D, Open Dm, Half Step Down, Full Step Down, +1 Semitone, +2 Semitones, Double Daddy, All 4ths, NST, and Ostrich.
No. The ear tuner mode plays reference tones for each string so you can tune by ear without a microphone. The microphone tuner mode is optional.
Cents deviation shows how far your string is from the correct pitch, measured in cents (hundredths of a semitone). A reading of 0 cents means perfectly in tune. Positive values mean sharp (too high), negative values mean flat (too low).
Yes — completely free. No account, no download, and no payment required. It runs entirely in your browser.
When you enable the mic tuner and allow microphone access, your browser captures audio input and runs a pitch detection algorithm on the sound in real time. It identifies the fundamental frequency of the note you are playing, compares it to the nearest string's target frequency, and displays the deviation in cents so you know whether to tune up or down.
DADGAD (listed as D Modal) tunes the strings to D, A, D, G, A, D from low to high. It produces a rich, open, modal sound popular in Celtic and fingerstyle guitar.
Drop B tuning lowers all strings by two and a half steps from standard, then drops the lowest string one further step to B. The resulting tuning from low to high is B, F#, B, E, G#, C#. It is popular in heavy metal for its deep, aggressive tone.
Open E tuning raises several strings so the guitar plays an open E major chord without fretting: E, B, E, G#, B, E from low to high. It is widely used in blues slide guitar.