Bass Tuner
Sound is analyzed only on this device. Nothing is recorded, sent, or stored.
Start with the 4th string, E1 (about 41.2 Hz). If low notes don’t register, hold your phone closer to the bass.
How to use it
Pluck E1, then A1, D2 and G2, one string at a time. The tuner picks whichever of the four strings is closest to what it hears. When the needle sits in the green center (within ±5 cents), you’re in tune.
Tap a string name to hear its reference tone and lock the tuner to that string. If your guitarist tunes down to E♭, choose "Bass half step down" from the tuning list.
Tuning the low notes
Phone microphones often struggle with very low frequencies. If E1 won’t register, bring the phone closer and pluck toward the neck rather than near the bridge. Plucking near the bridge brings out strong high overtones.
Twelfth-fret harmonics sound an octave above the open string, which gives the mic a higher note to work with. This page only looks for the four bass strings, though, so for harmonics open the main tuner page, choose "Chromatic (any note)" and tune to the octave above (E2, A2, D3, G3).
Common mistakes
Letting other strings ring. The needle wobbles. Mute the strings you aren’t tuning.
Reading the needle the instant you pluck. The tuner measures about 20 times a second and shows the middle value of the last five readings. Pluck once and give it a moment.
Tuning separately from the guitar. If you play together, use the same reference. The guitar’s low E2 is exactly one octave above your E1, so play both together and listen for the wobble to slow until you can hardly notice it.
Tuning by the hertz readout. The lower the note, the bigger 1 Hz becomes: at E1 (about 41.2 Hz), 1 Hz is more than 40 cents. Go by the cents on the needle, not the Hz number.
FAQ
What frequency is half step down? With A4 at 440 Hz, E♭1 is about 38.9 Hz. Pick it from the tuning list and all four targets drop a semitone.
What about the low B on a 5-string? This page only has 4-string presets. Use Chromatic on the main tuner page and tune the 12th-fret harmonic of the B string (B1).
Can I plug my bass in? This tuner listens through your device’s microphone. In a noisy room, a clip-on tuner that reads the instrument’s vibration is less affected by background sound.