Online Bass Tuner
Tune a 4-string bass to E A D G with your microphone. Built to read low notes cleanly - pluck one string and bring the needle to the middle.
🔒 Microphone audio is analysed live in your browser - it's never recorded or sent anywhere.
How it works
Allow the mic
Press Start tuner and allow microphone access - nothing is recorded.
Pluck one string
Play one open string firmly and let it ring - low notes need a moment to settle.
Centre the needle
Tighten to raise the pitch, loosen to lower it, until the needle turns green.
How to tune a bass guitar online
A standard 4-string bass is tuned E A D G - the same notes as the four lowest guitar strings, one octave lower. This tuner hears those low notes through your microphone.
Low E (4th string)
Pluck the thickest string and let it sustain. Tune it to E1 (about 41 Hz).
A string
The 3rd string is A1 (55 Hz).
D string
The 2nd string is D2 (73 Hz).
G string
The thinnest string is G2 (98 Hz).
Check again
Go across once more - the neck settles as the tension changes.
Frequently asked questions
What are the notes of a bass guitar?
A standard 4-string bass is E1, A1, D2, G2 - the same letter names as the lowest four guitar strings, one octave lower.
The low E won't register - why?
Very low notes are hard for small microphones to pick up. Play the harmonic at the 12th fret (touch the string lightly above the fret wire and pluck) - it's the same note an octave higher and reads easily.
Can I tune a 5-string or drop-tuned bass?
Yes - use Chromatic mode, which shows the nearest note for anything you play, including B0 or drop D.
Is my audio recorded?
No. The microphone signal is analysed live inside your browser and never saved or sent anywhere.
What's A4 = 440?
The reference pitch the whole scale is built from. 440 Hz is the modern standard; some orchestras use 442, and some people prefer 432. Change it if your band or recording uses a different reference.
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