Guitar Tuner
A chromatic tuner that listens through your microphone, shows how far each string is from pitch in cents, and says which way to turn the peg. Press a string to hear its reference tone and tune by ear instead, or do both: play the tone, then play the string and watch the bar. Four tunings are built in, standard, drop D, half step down and four-string bass, at a reference of A = 440, 432 or 442. The pitch is measured from the raw samples with autocorrelation, so it follows a string being turned rather than averaging it, and the samples are read in the page and dropped. Nothing is recorded, nothing is uploaded, and the stream closes when you stop or leave.
Tune with your microphone
Your browser asks for permission first, because no page may listen without it. The samples are read in the page and dropped: nothing is recorded and nothing is uploaded.
The microphone is closed. Press Start to tune with it, or Play to hear a reference tone.
Strings in each tuning
Every frequency here is at A = 440, the reference chosen above, and is the exact pitch the Play button sounds. Any string is tuned the same way: play it, watch the bar, and turn the peg until the needle sits in the green. Sharp means the string is too tight, so tune down; flat means too loose, so tune up.
| Tuning | Strings, low to high | Frequencies |
|---|---|---|
| Standard | E2 A2 D3 G3 B3 E4 | 82.4 Hz, 110.0 Hz, 146.8 Hz, 196.0 Hz, 246.9 Hz, 329.6 Hz |
| Drop D | D2 A2 D3 G3 B3 E4 | 73.4 Hz, 110.0 Hz, 146.8 Hz, 196.0 Hz, 246.9 Hz, 329.6 Hz |
| Half step down | Eb2 Ab2 Db3 Gb3 Bb3 Eb4 | 77.8 Hz, 103.8 Hz, 138.6 Hz, 185.0 Hz, 233.1 Hz, 311.1 Hz |
| Bass | E1 A1 D2 G2 | 41.2 Hz, 55.0 Hz, 73.4 Hz, 98.0 Hz |
Common questions
- Why does the browser ask permission before the tuner works?
- Because no web page is allowed to listen without being told it may. The prompt comes from your browser, not from this site, and the choice is stored by your browser against this address. Allow it, play one string, and the note should appear within a moment. If you blocked it by accident, click the microphone or lock icon in the address bar, set the microphone back to allow, and press Start again. The reference tones do not need the microphone at all: press any string chip, or the Play button, and it sounds whether or not you have allowed anything.
- Nothing is detected when I play. What should I do?
- Play one string on its own and let it ring, with the others muted under your palm. The detector looks for a single repeating period in the sound, and two strings ringing at once give it two, which it reports as No clear pitch rather than guess between them. Too quiet means the level reaching the browser is below the detector's floor: move closer to the microphone, or pick a different input from the list, because the system default is often a webcam or a monitor rather than the microphone you meant. A string that has nearly died away drops below the floor too, so pluck again rather than waiting.
- What do sharp and flat mean, and which way do I turn the peg?
- Sharp means the string is sounding higher than the note it should be, so it is too tight: turn the peg to loosen it, which the tool calls tune down. Flat means it is sounding lower, so it is too loose: tighten it, which is tune up. The bar shows the distance in cents, hundredths of a semitone, with the green zone at five cents either side of the target, and the sentence under the note says the same thing in words. Turn in small movements and let the string ring after each one, and tune up to the note from below when you can, because a string tuned down to pitch tends to slip flat as the slack works through the nut.
- Which tunings does it support?
- Standard (E2 A2 D3 G3 B3 E4), drop D (the low E down a tone to D2), half step down (every string a semitone flat: Eb2 Ab2 Db3 Gb3 Bb3 Eb4) and four-string bass (E1 A1 D2 G2). Pick one in the Tuning control and the string chips, the reference tones and the target the bar measures against all change with it. For a tuning that is not listed, the big note name is chromatic: it names whatever note is heard, so you can tune any string to any note by name and use the frequency readout, though the bar and the sentence are measured against the nearest string of the tuning selected.
- Does it work for bass and ukulele?
- Bass, yes: choose Bass and the four strings E1 A1 D2 G2 are the targets, and the detector reaches down to the low E at 41 Hz and a five-string's low B at 31 Hz. Below about 80 Hz the reading settles a little less sharply than it does higher up, because a low string repeats fewer times in each frame the detector sees, so give a bass string a moment to steady before you trust the last cent. There is a bass page with its own copy at guitar-tuner/bass. Ukulele has no preset, but the note name still works: tune each string until the display reads G4, C4, E4 and A4, and use the frequency readout rather than the bar, which is measured against guitar strings.
- What is the reference pitch, and should I change it from 440?
- The reference is the frequency of the A above middle C, and every other note is placed relative to it. 440 Hz is the international standard and is what almost every recording, tuner and other player uses, so leave it there unless you have a reason. 442 is what many orchestras and some pianos tune to, and 432 is used by people who prefer it. Changing the reference moves every string's target and every reference tone with it, and the frequencies in the table under the tool are recalculated to match, so the number you see is always the one the Play button sounds.
- Is any audio recorded or sent anywhere?
- No. The browser hands the page a frame of raw samples about thirty times a second, the page runs the pitch detector on that frame and drops it, and nothing is written to disk or sent to a server. Reference tones are generated in the page too. The only thing this tool remembers between visits is the tuning and the reference pitch you last chose, stored in your own browser. Pressing Listening stops the microphone track, which is what turns your browser's recording indicator off, and leaving the page does the same.
Pitch is measured from the raw microphone samples with autocorrelation, which resolves to about one cent for notes above 80 Hz in a quiet room; background noise and a decaying string widen that. Reference tones are exact. No audio is recorded or sent anywhere.