Bass tuner

Standard bass tuning is E A D G (E1, A1, D2, G2), thickest string to thinnest. Tap Use microphone and play one string: the needle shows flat (tighten) or sharp (loosen). Tap a string button to hear its reference note.

How to tune your bass

1. Tap Use microphone and allow access. Your audio is analyzed in the browser and never leaves your device.
2. Pluck the E string (the thickest) firmly and let it ring. Mute the others with your fretting hand.
3. Negative cents means flat: tighten. Positive means sharp: loosen past the note, then tune back up to it.
4. When the reading holds within 5 cents, the readout says "in tune". Move on to A, D and G.
5. Go around once more. Bass strings are heavy, and tuning one pulls the neck slightly.

If you're plugged into an amp, hold the phone or laptop near the speaker. An unplugged electric bass is quiet, so put the microphone close to the strings.

Standard bass tuning

Every bass string is five half steps (a perfect fourth) above the one below it. That even spacing is why the bass fretboard is so regular, and why tuning by ear is easy.

Tune by ear: the 5th-fret method

Get the E string right first, from the reference tone, a piano or a keyboard. Then:

1. Press the 4th string (E) at the 5th fret and match the open 3rd string (A) to it.
2. Press the 3rd string (A) at the 5th fret and match the open 2nd string (D) to it.
3. Press the 2nd string (D) at the 5th fret and match the open 1st string (G) to it.

Unlike guitar there's no exception: it's the 5th fret for every pair. You can also compare harmonics: the harmonic at the 5th fret of one string matches the harmonic at the 7th fret of the next string up. Harmonics ring longer and higher, so the slow wobble of two slightly different notes is easier to hear.

Five-string bass: the low B

A five-string bass adds a low B (B0) below the E. The low B vibrates at about 30.9 Hz, below the lowest pitch this tuner listens for (35 Hz), and too low for most phone microphones anyway. Tune it by ear instead: press the B string at the 5th fret and match it to the open E. Or play its 12th-fret harmonic (B, about 61.7 Hz), which the tuner can read.

Troubleshooting

• Nothing shows on the low E: small microphones hear little below 50 Hz. Use the 12th-fret harmonic, which sounds an octave higher (E, about 82.4 Hz).
• The note flickers: pluck with the side of your finger over the pickups, not near the bridge, and mute the other strings.
• The browser blocked the microphone: allow it in the site settings (the icon left of the address), then reload the page.
• In tune open, out of tune up the neck: that's intonation, adjusted at the bridge saddles. A shop setup fixes it.

Next steps

Learn where every note lives with bass fretboard notes, read bass lines on paper with bass clef notes, and lock in with the metronome. Tuning another instrument? Try the guitar tuner or the ukulele tuner, or see all free tools.

Updated September 2026.