How to use the bass tuner
- Press Start tuner and choose Allow when the browser asks for the microphone.
- Play one open string and mute the others with your fretting hand. Give low notes half a second: the tuner needs a moment of steady sound.
- Follow the arrow. “↑ Tune up” means tighten the string, “↓ Tune down” means loosen it. A string gets a ✓ after half a second in tune.
- If a low string won’t read, switch on Harmonic mode. Touch the string lightly over the 12th fret, pluck, then lift your finger. The harmonic is an octave higher, and small microphones hear it much better.
- To tune one string only, tap its button to lock it, or press its number (1 is the lowest string). Press 0 to go back to automatic.
No microphone? Choose Tune by ear and tap a string to hear its note.
Bass guitar tunings
Standard bass tuning, E A D G, sits exactly one octave below the four lowest strings of a guitar. A 5-string bass usually adds a low B below the E, and a 6-string adds a high C above the G as well.
| Tuning | Strings, low to high | Frequencies (Hz) |
|---|---|---|
| 4-string standard | E1 A1 D2 G2 | 41.20 · 55.00 · 73.42 · 98.00 |
| 5-string | B0 E1 A1 D2 G2 | 30.87 · 41.20 · 55.00 · 73.42 · 98.00 |
| 5-string high C | E1 A1 D2 G2 C3 | 41.20 · 55.00 · 73.42 · 98.00 · 130.81 |
| 6-string | B0 E1 A1 D2 G2 C3 | 30.87 · 41.20 · 55.00 · 73.42 · 98.00 · 130.81 |
| Drop D | D1 A1 D2 G2 | 36.71 · 55.00 · 73.42 · 98.00 |
| E♭ standard | E♭1 A♭1 D♭2 G♭2 | 38.89 · 51.91 · 69.30 · 92.50 |
| D standard (DGCF) | D1 G1 C2 F2 | 36.71 · 49.00 · 65.41 · 87.31 |
| Double bass, orchestral | E1 A1 D2 G2 | 41.20 · 55.00 · 73.42 · 98.00 |
| Double bass, solo | F♯1 B1 E2 A2 | 46.25 · 61.74 · 82.41 · 110.00 |
Drop D lowers only the E string, by a whole step, so the lowest three strings give a power chord with one finger. E♭ standard lowers every string a half step and D standard a whole step, to suit a singer or a heavier sound. After a big change, check every string twice: the neck’s tension shifts, so the first strings drift a little while you tune the rest.
A bass ukulele uses the same E A D G notes, so choose 4-string. For soprano, concert, tenor and baritone ukuleles, use the ukulele tuner. For guitar and other instruments, use the chromatic online tuner.
Why phones struggle with the low E and B
This online bass tuner works with a phone microphone, but the lowest strings are hard for any small mic. Many phone and laptop microphones pick up little below about 100 Hz, and the low E is 41.20 Hz. What reaches the tuner is mostly the string’s overtones at 82 Hz, 124 Hz and up. A tuner that follows the strongest pitch then reads the E an octave too high.
This tuner checks each reading against the strings of your tuning and moves it down an octave when the lower note fits much better. It also listens to a longer stretch of sound. One cycle of B0 lasts 32 ms, and a pitch detector needs a few cycles, so the tuner analyzes about 171 ms at a time (8,192 samples at 48 kHz). That’s why a low string takes a moment, and why the tuner shows “Listening to a low note…” while it waits.
If a string still won’t read:
- Move closer. Hold the phone near the bass body, or near the amp’s speaker if you play through one.
- Use Harmonic mode. 12th-fret harmonics sound an octave higher, where small mics work better.
- Plug in. Connect the bass to an audio interface and choose it under Microphone in Settings. A direct signal keeps the full low end.
- Quiet the amp between notes. A steady hum from the amp or the mains can cover the low strings.
- Check the battery. An active bass with a weak battery sounds dull and distorted, which makes any tuner jumpy.
If the level meter hardly moves at all, test your microphone first.
Tuning a bass by ear
Tune one string to a reference first: choose Tune by ear and tap the low E, or use a piano or a tuning fork. Then use the 5th-fret method:
- Press the E string at the 5th fret. That note is A: tune the open A string to match it.
- The 5th fret of the A string gives D for the open D string, and the 5th fret of the D string gives G.
- In drop D, press the low D string at the 7th fret to get the A.
Harmonics are often easier to hear on a bass. Touch the E string over the 5th fret and the A string over the 7th fret, and pluck both. Both harmonics sound an E3 near 165 Hz. Turn the A string until the wobble between them slows down and stops. In equal temperament the two notes are about 2 cents apart, so a very slow beat, about one every five seconds, is normal.
Checking intonation at the 12th fret
Intonation is how well the fretted notes match the open strings. When it’s off, the bass is in tune on open strings and still sounds sour higher up the neck. The 12th fret is the test point: the harmonic there is exactly one octave above the open string, and the fretted note should match it.
- Tune the open string.
- Open Intonation check, choose the string and press Start intonation check.
- Play the 12th-fret harmonic, then the note fretted at the 12th fret, with the same pluck.
If the fretted note is sharp, move that string’s saddle back, away from the neck. If it’s flat, move the saddle toward the neck. Turn the screw a little, retune the open string and check again. Old strings give confusing results, so fit new strings first and let them settle for a day.
Double bass: orchestral and solo tuning
An orchestral double bass uses the same notes as a bass guitar: E1 A1 D2 G2. For solo pieces, many players tune every string a whole step higher, to F♯1 B1 E2 A2, usually with lighter solo strings. Choose Double bass, orchestral or Double bass, solo in the Tuning menu.
Upright bassists often tune with harmonics: a quarter of the way along the lower string and a third of the way along the next one, the same pair of notes as the 5th and 7th frets on a bass guitar. Tune the open strings without vibrato, so the reading can settle.