Free · 4, 5 and 6 strings

Bass Tuner

Tune your bass guitar online with the microphone or by ear. This free bass tuner hears which string you play and shows how far it is from E, A, D or G, to the cent. It also tunes five-string basses down to low B, six-strings, drop D and half-step down. Phone microphones struggle with the lowest notes, so the tuner also reads a string's 12th-fret harmonic as that string.

  • 5tunings
  • 31 Hzdown to low B
  • ±1cent precision
Start tuning

Tune Your Bass Online

Tap Start tuner and allow the microphone. Pluck one open string with your thumb and let it ring. If the needle won't settle on a low string, play its 12th-fret harmonic instead.

Reference pitch
A4 = 440 Hz
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Tap Start tuner, allow the microphone, then play one string.

 

Bass Fretboard Notes

Every note on the bass from open to the 12th fret, in the tuning you chose. The note you play lights up wherever else it sits on the neck. It's useful for learning the fretboard and checking a fretted note.

Bass fretboard notes, G string at the top, frets 0–12 (Standard 4-string)
0123456789101112
G2 G2G#2A2A#2B2C3C#3D3D#3E3F3F#3G3
D2 D2D#2E2F2F#2G2G#2A2A#2B2C3C#3D3
A1 A1A#1B1C2C#2D2D#2E2F2F#2G2G#2A2
E1 E1F1F#1G1G#1A1A#1B1C2C#2D2D#2E2

Teaching? Put this bass tuner on your class site, free. Get the embed code

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Standard Bass Tuning: E A D G

Held to play, the thickest string, E, is on top, nearest your face. Then come A and D, and the thin G string at the bottom. Each string is a perfect fourth above the one before. It's the same as the lowest four strings of a guitar, one octave lower.

Standard 4-string: E A D G

The tuning of almost every four-string bass: the same notes as a guitar's four lowest strings, an octave lower.

4th string
E1 · 41.20 Hz
3rd string
A1 · 55.00 Hz
2nd string
D2 · 73.42 Hz
1st string
G2 · 98.00 Hz

Other tunings in the tuner

  • 5-string (low B) (B0 E1 A1 D2 G2) A low B below the E, a perfect fourth down, for the five notes under a four-string's range.
  • 6-string (B0 E1 A1 D2 G2 C3) Low B and a high C, still all in fourths. Common in jazz and fusion for chords and high melodies.
  • Drop D (D1 A1 D2 G2) Only the E string drops a whole step to D. One finger plays power-chord roots, and you get a low D for rock and metal.
  • Half-step down (Eb1 Ab1 Db2 Gb2) Every string a semitone lower (E♭ A♭ D♭ G♭), to match guitarists who tune down for a heavier sound or to suit a singer.

How to Tune a Bass Guitar with This Tuner

Tune with the bass unplugged, or through your amp with every effect off. Either way, the tuner needs a clean note.

  1. Pick your tuning

    Standard for a four-string, 5-string if you have a low B, or Drop D or Half-step down if a song calls for it. The string buttons and fretboard change to match.

  2. Get the mic close

    Tap Start tuner and allow the microphone. An unplugged electric bass is quiet, so hold the phone or laptop near the strings, by the end of the neck. Through an amp, any distance works.

  3. Pluck with your thumb

    Pluck each open string with the side of your thumb, over the end of the neck. That gives a round note with a strong fundamental, which the tuner reads more steadily than a bright pick attack.

  4. Read it as it rings

    A bass note goes sharp for a moment at the attack, then settles. Watch the needle half a second after you pluck. Tune up to the note: if it's sharp, go below and come back up.

  5. Use harmonics for the low strings

    If the E or B string won't settle, touch it lightly right above the 12th fret and pluck. That harmonic is an octave higher, much easier for a phone to hear, and the tuner reads it as the open string.

How to Tune a Bass by Ear

Tune one string to the tone, then tune the others to it. Use the fifth-fret method for most basses, or harmonics for more accuracy.

  1. Tune the E (or A) to the tone

    Tap the E string above and turn on Repeat the tone. Tune your E until the two notes stop beating against each other. On small speakers, tune the A string first. It's easier to hear.

  2. Fifth fret, next string

    Fret the E string at the 5th fret (A) and tune the open A to it. Fret the A string at the 5th fret (D) and tune the open D. Fret the D string at the 5th fret (G) and tune the open G. On a five-string, the B string's 5th fret gives you E.

  3. Or tune with harmonics

    The harmonic at the 5th fret of the E string matches the harmonic at the 7th fret of the A string (both E). Do the same for A–D and D–G. Harmonics ring longer than fretted notes, so the beating is easier to hear.

  4. Check with octaves

    Play the open E with the D string at the 2nd fret, which is an E an octave up. They should sound like one note. Do the same for A with the G string at the 2nd fret.

What This Bass Tuner Does

Made for the problem online bass tuners skip: a phone microphone that can barely hear a bass.

Reads 12th-fret harmonics

Play a string's harmonic and the tuner treats it as the open string, an octave down. Low E and low B tune reliably even on a phone.

Start tuning

  • Down to low B (31 Hz)

    The detector looks for the longest repeating period in the sound. That's the fundamental, even when the phone's mic picks up mostly overtones.

  • Five tunings

    Standard four-string, five-string, six-string, drop D and half-step down. The string buttons, tones and fretboard map follow the tuning you choose.

  • Auto string detection or lock

    The tuner works out which string you plucked. If one is far out, turn auto-detect off and tap the string to lock the tuner to it.

  • Plucked reference tones

    Tap a string to hear its target note as a plucked bass string. Turn on Repeat and it replays every two seconds while you turn the machine head.

  • Adjustable reference A

    440 Hz by default, or anything from 415 to 466 Hz to match a piano, a recording or a band that tunes differently.

  • Live fretboard map

    All the notes to the 12th fret, with dot positions marked. The note you play lights up everywhere it appears.

Low Strings and Other Snags

The low E or B won't register

Phone and laptop microphones barely pick up notes below about 60 Hz, and the low E is 41 Hz (low B 31 Hz). Play the 12th-fret harmonic instead. The tuner reads it as the open string. Or play through an amp and put the mic near the speaker.

The note goes sharp, then flat

Every plucked bass note is sharp at the attack and settles as it rings. Pluck more gently, and read the needle once it has stopped moving. Heavy attacks on a low string can be 10 cents sharp for the first instant.

In tune open, out of tune at the 12th fret

Compare the open string with the note fretted at the 12th fret, which should be exactly an octave up. If the fretted note is sharp, the string's speaking length is too short: move the saddle away from the neck. If it's flat, move the saddle towards the neck. That's a saddle adjustment, not a tuning problem.

It reads the wrong string

A string far out of tune can land closer to the next string's note. Turn off Auto-detect string and tap the string you're tuning to lock the tuner to it. Then bring it into range.

Effects get in the way

Octave, chorus and synth pedals confuse every tuner. Tune with them bypassed, or unplugged.

Free, in Your Browser

  • Nothing to install Runs in Chrome, Safari, Edge and Firefox on a phone, tablet or computer. No app, no plugin.
  • Sound stays on your device The microphone is analysed in your browser. No audio is recorded, uploaded or stored.
  • No account No sign-up and no limits. Open the page and tune.
  • Works without a mic Plucked string tones let you tune by ear when the microphone is blocked.

Bass Tuning Questions

What are the notes of the bass guitar strings?

E, A, D and G, from the thickest string to the thinnest: E1 (41.2 Hz), A1 (55 Hz), D2 (73.4 Hz) and G2 (98 Hz). They're the same note names as a guitar's four lowest strings, one octave lower.

How do I tune a 5-string bass?

Choose 5-string (low B) in the tuning menu. The strings are B, E, A, D and G. The low B is 30.9 Hz, below what most phone mics hear well, so tune it with its 12th-fret harmonic or through an amp.

How do I tune a 6-string bass?

Choose 6-string. The tuning is B E A D G C: a five-string plus a high C, all in fourths.

What is drop D on bass?

Only the E string is lowered a whole step, to D. The other strings stay A D G. Pick Drop D, tune the lowest string until it reads D, and check the A string again afterwards.

Why can't the tuner hear my low E?

The low E is 41 Hz and the low B is 31 Hz. Most phone and laptop microphones lose sensitivity below about 60 Hz. Pluck with your thumb near the neck for more fundamental, play the 12th-fret harmonic (which this tuner reads as the open string), or tune through an amp.

Can I tune an electric bass without plugging it in?

Yes. Hold the phone or laptop close to the strings near the end of the neck and pluck firmly. The unplugged sound is quiet but clean, which is what the tuner needs.

Is a bass tuned the same as a guitar?

A four-string bass uses the note names of the guitar's four lowest strings (E A D G), one octave lower. The guitar adds B and E on top.

Does this tuner work for upright (double) bass?

Yes. A double bass in orchestral tuning is E A D G at the same pitch as a bass guitar, so use Standard 4-string. Bow or pluck the open string and read it as it rings.

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