Free online tool
Guitar Tuner
Free online guitar tuner: tune by microphone in standard EADGBE, Drop D, DADGAD, Open G, Open D, half-step down, D or C standard. Nothing is recorded.
Press the button and your browser will ask to use the microphone. The tuner needs it to hear your guitar. Sound is analysed on your device and is never recorded or sent anywhere.
Strings
Tap a string to tune to it (this turns automatic detection off), or the ▶ button to hear the reference pitch.
Guitar tunings and string frequencies
Strings in the order they are listed, A4 = 440 Hz, equal temperament. Each tuning is a row.
| Tuning | String 1 | String 2 | String 3 | String 4 | String 5 | String 6 |
|---|---|---|---|---|---|---|
| Standard (EADGBE) | E282.41 Hz | A2110.00 Hz | D3146.83 Hz | G3196.00 Hz | B3246.94 Hz | E4329.63 Hz |
| Drop D (DADGBE) | D273.42 Hz | A2110.00 Hz | D3146.83 Hz | G3196.00 Hz | B3246.94 Hz | E4329.63 Hz |
| DADGAD | D273.42 Hz | A2110.00 Hz | D3146.83 Hz | G3196.00 Hz | A3220.00 Hz | D4293.66 Hz |
| Open G (DGDGBD) | D273.42 Hz | G298.00 Hz | D3146.83 Hz | G3196.00 Hz | B3246.94 Hz | D4293.66 Hz |
| Open D (DADF#AD) | D273.42 Hz | A2110.00 Hz | D3146.83 Hz | F#3185.00 Hz | A3220.00 Hz | D4293.66 Hz |
| Half step down (Eb) | Eb277.78 Hz | Ab2103.83 Hz | Db3138.59 Hz | Gb3185.00 Hz | Bb3233.08 Hz | Eb4311.13 Hz |
| D standard (whole step down) | D273.42 Hz | G298.00 Hz | C3130.81 Hz | F3174.61 Hz | A3220.00 Hz | D4293.66 Hz |
| C standard (two steps down) | C265.41 Hz | F287.31 Hz | Bb2116.54 Hz | Eb3155.56 Hz | G3196.00 Hz | C4261.63 Hz |
About the Guitar Tuner
Guitar Tuner is a free online guitar tuner that listens through your microphone and shows how close each string is to its target note. It runs in your web browser, needs no sign-up, and records nothing you play. You can tune to standard EADGBE, Drop D, DADGAD, Open G, Open D, half-step down, D standard or C standard.
Use it as a guitar tuner online when you want a quick check before playing, without installing anything. It works with an electric guitar too, as long as the sound reaches the microphone. Each tuning lists its strings with their notes, so you always know which string you are working on.
How to use the Guitar Tuner
- Press Start microphone and allow access when the browser asks.
- Choose your tuning in the Tuning control. For a standard guitar, pick Standard (EADGBE).
- Leave Detect the string automatically on, or tap a string under Strings to tune to that string.
- Pluck one open string and let it ring. The needle shows how many cents you are from the target note.
- Turn the tuning peg slowly until the needle sits in the green centre band and the display says In tune. Then move to the next string.
Use A4 reference (Hz) if you play along with an instrument that is not at 440 Hz. The range is 415 to 466 Hz. If you need a sound to tune by ear, press ▶ Play on the Reference note.
Tune in a quiet room and pluck one string at a time. Approaching each note from below gives a steadier reading, so if you go past the note, loosen the string a little and tune up again.
Pluck at medium strength and let the note ring. The first instant after the pick hits is the least stable, so wait a moment before you judge the reading. If the display jumps to a note an octave away, pluck more gently or move the microphone closer.
New strings stretch and drift, so recheck the whole set after a few minutes.
For an electric guitar, the tuner works if the sound reaches the microphone, for example from the amplifier.
How does a guitar tuner measure pitch?#
A tuner measures the frequency of a string, the number of vibrations per second in hertz, and compares it with the frequency of the note you want. At A4 = 440 Hz, the low E string should read 82.41 Hz and the high E string 329.63 Hz. The needle then shows whether the reading is above or below the target.
What are the notes of a guitar in standard tuning?#
From the thickest string to the thinnest, standard tuning is E2, A2, D3, G3, B3, E4, or E A D G B E. Neighbouring strings are a perfect fourth apart, except G to B, which is a major third. The number after each letter gives the octave, so E2 sounds lower than E4.
What tunings for guitar does the tool support?#
The tool covers eight tunings: Standard (EADGBE), Drop D (DADGBE), DADGAD, Open G (DGDGBD), Open D (DADF#AD), Half step down (Eb), D standard (whole step down) and C standard (two steps down). Alternate tunings change one or more strings from the standard pattern.
DADGAD lowers the 6th, 2nd and 1st strings: low E to D, B to A and high E to D. Its open strings sound a Dsus4 chord. Open G and Open D tune the open strings to a G or D major chord. Half step down, D standard and C standard lower every string by one, two or four semitones, so your chord shapes stay the same at a lower pitch.
What do cents and the In tune display mean?#
A cent is one hundredth of an equal-tempered semitone, so an octave is 1200 cents. The meter runs from −50 to +50 cents around the target. Negative means the string is flat (too low), and positive means it is sharp (too high). The display says In tune when the pitch stays within 5 cents of the target for about a third of a second.
Why does the tuner say my string is between two notes?#
The tuner shows the pitch it hears. A string that is far out of tune sits between notes, so tune it roughly by ear with the reference tone first, then fine-tune with the needle. Pluck at medium strength and let the note ring, because the first instant after the pick hits is the least stable.
Approach the note from below. If you go past it, loosen the string a little and tune up again. This helps the string stay put.