Guitar Tuner

Infinite Guitar's online guitar tuner is a free tuner that listens to your guitar through your microphone and shows you, string by string, whether each one is in tune. It runs right in your browser on a computer, tablet or phone, with nothing to download, and it works for acoustic and electric guitars with 6, 7, 8 or 9 strings.

How to tune a guitar with our online tuner

1. Press the mic button. Your browser asks to use the microphone the first time. The sound never leaves your device.
2. Pick your strings and tuning. Standard tuning on 6 strings is already set. Choose 7, 8 or 9 strings, or an alternate tuning like Drop D, Open G or DADGAD, under the tuner.
3. Play one open string and let it ring. You don't have to pick the string first. The tuner works out which one you're playing and shows its note in the middle.
4. Watch the gauge. If the light is left of center the string is flat, so tighten it. If it's right of center the string is sharp, so loosen it. When it turns green you're in tune.
5. Go string by string. The string turns green while it's in tune. Strings drift as you play, so check them again whenever something sounds off.

Want to hear what a string should sound like? Press it under the gauge and the tuner plays its note. To have the tuner listen for one string only, set Detect string to Manual and press the string you're tuning. Playing an electric guitar? Play it through an amp, or hold your phone or laptop close to the strings.

Standard guitar tuning notes

Standard tuning, from the thickest string to the thinnest, is E A D G B E. A popular way to remember it is "Eddie Ate Dynamite, Good Bye Eddie". The small number after each note is its octave, so the two E strings are two octaves apart.

Alternate guitar tunings

Retuning one or more strings changes which chords fall under your fingers and how the guitar rings. Pick a tuning type under the tuner, then use Pitch to move the whole guitar down or up in half steps. Drop on a 7-string tuned down 1½ steps, for example, gives you Drop F♯ (F♯ C♯ F♯ B E G♯ C♯). The most popular types:

• Drop D (D A D G B E): only the low E string drops a whole step to D. Power chords on the bottom three strings become a one-finger shape, which is why it's everywhere in heavy rock.
• Half step down (E♭ A♭ D♭ G♭ B♭ E♭): Standard with Pitch set to ½ step down. It sounds a little darker and heavier, and bends feel easier.
• Full step down (D G C F A D): Standard 1 step down, for an even deeper sound with the same chord shapes.
• Drop C (C G C F A D): Drop 1 step down, a favorite for metal riffs. Keep going for Drop B, Drop A and lower.
• DADGAD: an open, ringing tuning that's popular in folk and Celtic music (you'll find it under Open). Richard Lundmark walks you through it in Alternate Tunings Part 3: DADGAD, and takes it further in Part 4: DADAAD.
• Open G, Open D, Open E and Open C: the open strings spell out a full chord, so you can strum without fretting anything and play slide with one finger across the neck. Start with Alternate Tunings Part 1: Open E Major or Slide Guitar: Open Tuning.

Once you're in a drop tuning, Mike Salow's Drop Tuned Chord Voicings shows you chords that only work there. Using a tuning of your own? Pick Custom and raise or lower each string until it matches, and the tuner remembers it for next time. Or pick Chromatic and it works as a chromatic tuner, showing the nearest note to whatever you play.

Tuning a 7, 8 or 9-string guitar

Extended range guitars keep the six strings of standard tuning and add lower strings underneath, each one about a fourth below the next. Set Strings to 7, 8 or 9 and the tuner switches to their standard tuning. Drop gives you Drop A, Drop E or Drop B, and Pitch takes any of them lower, all the way to Drop F♯ and beyond.

Those low strings move slowly, so give the tuner a second to settle on them, and pluck firmly near the neck so the note comes through clearly. For a heavy low end to try them out on, there's Lucas Fowler's Drop B Tuning Etude and Al Joseph's Djent Grooves.

Guitar tuning tips

• Tune up to the note. If a string is sharp, loosen it until it's a little flat, then bring it back up. The string settles against the tuning peg and stays in tune longer.
• Stretch new strings. Fresh strings keep going flat until they've stretched. Richard Lundmark shows you how to change and break them in, in String Change: Regular Tuners and Breaking In the Strings.
• Tune in playing position. Hold the guitar the way you play it, since leaning on the neck or resting it flat can pull the strings slightly.
• Check the 12th fret. If open strings are in tune but chords higher up sound off, the guitar's intonation needs adjusting. Learn how in Intonation.
• Use a quiet room. Background noise and other instruments can confuse any tuner. Play one string at a time and let it ring.
• Playing with other people? Almost everything is tuned to A4 = 440 Hz. If a piano or a recording sits a little higher or lower, match it with A4 calibration.

Guitar tuner FAQ

Now that you're in tune, keep your timing tight with our online metronome, look up any shape in the guitar chord chart, or jump into our free guitar lessons.