Online Guitar Tuner (Chromatic)
Play a string and see the note, how far off it is and which way to turn the peg.
Tuner
Allow the microphone, then play one string at a time, close to it; the needle settles in the green zone when the string is in tune. The sound is analysed on your device and never recorded or uploaded.
Press Start tuning
The tuner picks the string nearest to what it hears. Press a string to tune only that one (useful when a string is far off), or ▶ to hear its note.
About the Online Guitar Tuner (Chromatic)
A microphone tuner for guitar (standard, drop D, half step down, open G, open D and DADGAD), bass (4- and 5-string), ukulele (high G, low G and baritone), violin, viola and cello — or chromatic mode for any instrument or voice. Play one string: the tuner shows the note, how many cents sharp or flat it is, which string it thinks you are tuning and whether to tune up or down. The reference pitch A4 can be set from 432 to 446 Hz.
The pitch is found with the McLeod Pitch Method, which locks onto the fundamental even when a phone microphone barely picks up the low note itself. The sound is analysed in your browser and is never recorded or uploaded; the browser’s voice processing (noise suppression, echo cancellation, automatic gain) is turned off so it cannot colour the tone.
How to use it
- Choose your instrument and tuning (or Chromatic), and the reference pitch if it is not 440 Hz.
- Press Start tuning and allow the microphone when the browser asks.
- Pluck one string and let it ring, close to the microphone. The tuner finds the nearest string; press a string to tune that one only.
- Turn the peg until the needle stays in the green zone (within ±5 cents) and the display says In tune ✓. If the reading is flat, tune up; if sharp, tune down.
- Repeat for every string, then check them once more: tightening one string changes the tension on the neck a little.
Examples
Guitar standard · pluck string 6
E2 · −12 cents · “Flat — tune up” (target 82.41 Hz)
Guitar drop D · string 6
Target D2 = 73.42 Hz; the other strings stay A2 D3 G3 B3 E4.
String 5 sounding about 98 Hz
A2 · −200 cents · “Flat — tune up (2.0 semitones)”: still the A string, two semitones low.
Reference pitch 432 Hz
Every target moves down by 31.8 cents: E2 becomes 80.91 Hz.
Common uses
- Tuning acoustic and electric guitars, basses and ukuleles before playing or recording.
- Changing to drop D, open G, open D or DADGAD for a song.
- Tuning violin, viola or cello strings, or matching a piano tuned at 442 Hz.
- Checking the pitch of a voice, a wind instrument or any single note in chromatic mode.
How the pitch is found
The tuner reads the latest 2,048 to 8,192 microphone samples (enough for about three periods of the lowest string) about 25 times a second and applies the McLeod Pitch Method (P. McLeod and G. Wyvill, A Smarter Way to Find Pitch, ICMC 2005). It computes the normalised square difference function n′(τ) = 2·r′(τ) / m′(τ), where r′ is the autocorrelation and m′ the sum of the squared samples over the overlapping part; n′ reaches 1 at lags where the sound repeats exactly. Of the highest point of each positive lobe (the “key maxima”), it takes the first that reaches 93 % of the highest — the period of the fundamental, not of a louder harmonic — and refines it between samples with a parabola. Readings with low clarity (noise) are ignored, and the median of the last five readings steadies the needle.
Notes, cents and A4
Targets use twelve-tone equal temperament: f = A4 × 2^((n − 69) / 12), where n is the MIDI note number. ISO 16:1975 sets A4 at 440 Hz; some orchestras tune to 442 Hz, and some players prefer 432 Hz. A cent is a hundredth of a semitone: the offset is 1200 × log₂(f / f_target). Differences under about 5 cents are hard to hear in a single note, which is why the green zone is ±5 cents; for chords that ring cleanly, get as close to 0 as you can.
The tunings
- Guitar standard: E2 82.41 · A2 110.00 · D3 146.83 · G3 196.00 · B3 246.94 · E4 329.63 Hz.
- Drop D: the low E down to D2 (73.42 Hz). Half step down: every string a semitone lower (E♭2 … E♭4).
- Open G: D2 G2 D3 G3 B3 D4. Open D: D2 A2 D3 F♯3 A3 D4. DADGAD: D2 A2 D3 G3 A3 D4.
- Bass: E1 A1 D2 G2, with B0 (30.87 Hz) on a 5-string.
- Ukulele: G4 C4 E4 A4 (re-entrant high G), or G3 C4 E4 A4 (low G); baritone D3 G3 B3 E4.
- Violin G3 D4 A4 E5 · Viola C3 G3 D4 A4 · Cello C2 G2 D3 A3.
Guitar strings are numbered from the thinnest: string 1 is the high E, string 6 the low E.
Tips for a steady reading
Pluck firmly with the fleshy part of the thumb and let the string ring; the first moment of a pluck is slightly sharp. Mute the other strings with your hand, and tune in a quiet room. Tune up to the note: if a string is sharp, go below the target and come back up, so the string settles in place. Low bass strings are hard for phone microphones to pick up; hold the phone near the body of the instrument, or use a headset or USB microphone.
Limitations
- One note at a time: it cannot tune from a strummed chord.
- Loud background noise, a fan or other instruments can stop it from finding a clear pitch.
- Built-in microphones of phones and laptops pick up little of the lowest bass notes; the tuner still finds them from their harmonics, but the reading may take longer to settle.
- Bluetooth headsets may lower the sound quality of the microphone; a wired or built-in microphone works better.
- It tunes to equal temperament only; there are no sweetened or historical temperaments.
Privacy
Everything happens in your browser. What you enter or open here is not uploaded or stored by MySmartCoPilot.
Frequently asked questions
How do I tune a guitar with this tuner?
Choose Guitar: Standard, press Start tuning, allow the microphone and pluck the low E string. When the reading says flat, tighten the string (tune up); when sharp, loosen it. Stop when the needle stays in the green zone, then do the other five strings the same way.
How accurate is it?
In our tests with synthetic string tones — with and without the fundamental, and with added noise — it reads within half a cent to two cents. With a real instrument the reading also moves a little as each pluck rings out, so let the note ring for a second before you judge it.
Why does it show the wrong string or note?
When a string is more than half a semitone away from its target, the nearest string may be a different one. Press the string you are tuning to lock it: the tuner then shows how far that string is from its note, even several semitones away.
What does A4 = 440 Hz mean, and should I change it?
It is the reference that sets every other note. Leave it at 440 Hz unless you play with a piano, band or recording that is tuned differently; then match their A (for example 442 Hz).
Is my microphone audio recorded or sent anywhere?
No. The sound is analysed in your browser as it arrives and immediately discarded; nothing is recorded, stored or uploaded. The microphone switches off when you press Stop tuning or leave the page.
The page cannot use my microphone. What can I do?
The page explains the fix for your browser and system when access is blocked. Usually: allow the microphone in the site settings (the icon next to the address), check the system privacy settings for the microphone, and close other apps that are using it.