Online bass tuner

Bass string notes

Frequencies are calculated with the reference A at 440 Hz. If your group tunes to a different reference, such as 442 Hz, adjust it with the − and + buttons next to “A = 440 Hz” and the tuner shifts every note.

The bass and the guitar

E1, A1, D2 and G2 are the same notes as the guitar's four lowest strings, an octave lower. That's why a guitarist instantly recognizes bass shapes. It is also the double bass tuning, which the electric bass inherited. Neighboring strings are a perfect fourth apart: the note at the 5th fret of one string is the open note of the next.

Tuning with harmonics

Harmonics are the most common way to check a bass by ear: the 5th-fret harmonic on one string should sound the same as the 7th-fret harmonic on the next (higher) string. If you hear a wavering between the two, one of the strings is out of tune.

With this tuner you can also play the 12th-fret harmonic (an octave up) or the 5th-fret harmonic (two octaves up) on each string: the tuner recognizes them as that same string and tells you how many octaves higher they sound. This is very handy when your phone's microphone has trouble picking up the open E string. Have a five-string bass? Use the 5-string bass tuner.

When the bass is in tune on open strings but not on the frets

If you changed string gauge or the bass went through a major climate change, check its intonation: tune the open string and compare it with the note at fret 12, which should be exactly the same note one octave higher. If fret 12 is sharp, move that string's bridge saddle away from the neck; if flat, move it toward the neck. This is a precise screwdriver adjustment, so leave it to a technician if you are unsure.

How to tune your bass with this tuner

1. Tap Enable microphone and accept the browser's permission request. The sound is analyzed on your device: it isn't recorded or sent anywhere.
2. Leave the tuner on Auto so it recognizes which string you're playing, or tap a note to lock it (tap it again to go back to Auto).
3. Play a single open string with medium force and let it ring.
4. If the needle is to the left, the note is flat: tune up. If it's to the right, tune down. Anywhere between −5 and +5 cents counts as in tune.
5. Once a string stays in tune for a moment, its button gets a green check mark. Keep going until every string has one.
6. Use the speaker icon under each note to hear the reference and train your ear.
7. Go over every string again at the end: the tension of some strings shifts the others slightly.

Tips for tuning your bass

• Tune with the bass plugged into the amp at a moderate volume: the microphone picks up low notes better.
• Use the 12th-fret harmonic if the open note is too low for your microphone.
• Tune up to the note so the string settles on the tuning peg.
• If the open strings are in tune but the 12th fret doesn't give an exact octave, the bridge intonation needs adjusting.

Common tuning problems

• The needle jumps between notes: play a single string, a little more softly, and wait for the sound to settle. The first instant of every note always sounds slightly sharp.
• It doesn't pick up the low strings: phone microphones struggle with low frequencies. Hold your phone closer to the instrument or play the harmonic at the middle of the string (12th fret): the tuner recognizes it as the same string and tells you it sounds an octave higher.
• The open strings are in tune, but what you play sounds off: check that no string is in the wrong octave and that your strings aren't old. If it still sounds wrong, ask your teacher or a luthier to check the instrument's intonation.
• It goes out of tune right away: new strings keep stretching for several days, and changes in temperature and humidity shift the tuning. Tune in the same place where you're going to play.
• The browser doesn't ask for the microphone: check the site permissions in your browser settings and make sure no other app is using the microphone.

Frequently asked questions