Free online tool
Bass Tuner: 4-String, 5-String and Drop D
Free online bass guitar tuner using your microphone: 4-string EADG, 5-string BEADG and Drop D, down to low B (30.87 Hz). Nothing is recorded or uploaded.
Press the button and your browser will ask to use the microphone. The tuner needs it to hear your bass. Sound is analysed on your device and is never recorded or sent anywhere.
Strings
Tap a string to tune to it (this turns automatic detection off), or the ▶ button to hear the reference pitch.
Bass tunings and string frequencies
Strings in the order they are listed, A4 = 440 Hz, equal temperament. Each tuning is a row.
| Tuning | String 1 | String 2 | String 3 | String 4 | |
|---|---|---|---|---|---|
| 4-string standard (EADG) | E141.20 Hz | A155.00 Hz | D273.42 Hz | G298.00 Hz | |
| 5-string standard (BEADG) | B030.87 Hz | E141.20 Hz | A155.00 Hz | D273.42 Hz | G298.00 Hz |
| Drop D (DADG) | D136.71 Hz | A155.00 Hz | D273.42 Hz | G298.00 Hz |
About the Bass Tuner
Bass Tuner is a free online bass guitar tuner that listens through your microphone and shows how close each string is to its target pitch. It runs in your web browser with no sign-up, so you can start bass tuning online without installing anything. It covers standard 4-string bass (EADG), 5-string bass (BEADG) and Drop D, and reads down to low B at 30.87 Hz. Whether you need an e bass tuning reference for a 4-string or a bass tuner 5 string setup, the same page handles both. Tune in a quiet room and pluck one string at a time for the clearest reading. Nothing is recorded or uploaded.
How to use the Bass Tuner
- Press Start microphone and allow access when the browser asks.
- Choose 4-string, 5-string or Drop D from Tuning.
- Pluck one open string at medium strength and let it ring. Low strings take a moment to settle, so wait for the reading to steady.
- Turn the peg until the needle is in the green band and the display says In tune. Tune up to the note: if you overshoot, loosen the string and approach it from below.
- Move to the next string and repeat. When you reach the last string, go back and check the earlier ones, because changing one string’s tension can move the neck slightly.
Set A4 reference (Hz) if you need a reference other than 440 Hz. To hear the reference pitch, choose a note in Reference note and press ▶ Play. Use a speaker that can reproduce low notes, since small speakers make the fundamental of E1 hard to hear.
Keep the room quiet, pluck one string at a time, and wait for the reading to settle before you adjust anything. These habits matter on bass because low notes take longer to read, and a phone or laptop microphone picks up very low frequencies poorly.
- If the display jumps between notes, play the harmonic at the 12th fret, which sounds one octave higher, or hold the microphone near your amp speaker.
What are the notes of a 4-string bass?#
A standard 4-string bass is tuned E1, A1, D2, G2, which is E A D G. Each string sits a perfect fourth above the one before it. These are the same note names as the four lowest guitar strings, but one octave lower. With A4 = 440 Hz, the low E vibrates at 41.20 Hz.
How is a 5-string bass tuned?#
A 5-string bass adds a low B0 below the E, so it is tuned B0, E1, A1, D2, G2. The added B0 vibrates at 30.87 Hz when A4 = 440 Hz, which is much lower than any note on a 4-string bass. Its extra low range is the reason 5-string players often need a tuner that reads very low frequencies.
What is drop D bass tuning?#
Drop D bass tuning lowers the E string a whole step to D1 (36.71 Hz), giving D A D G. The A, D and G strings stay where they are. It is a common choice for heavier, lower-sounding parts.
Why is the low string hard for a tuner to read?#
Low notes have long wave cycles and weak upper harmonics, which makes them harder for a microphone to pick up. Small built-in microphones are especially poor at very low frequencies. The tool also listens to a longer slice of sound for bass than for guitar or ukulele, so the needle responds a little more slowly.
How does the meter show whether a string is in tune?#
The meter shows −50 to +50 cents around the target. A cent is a hundredth of a semitone. In tune appears when the pitch stays within 5 cents for about a third of a second. On low strings, 5 cents on E1 is only about 0.12 Hz, so the error looks small in Hz even when the needle is slightly off.
How do you tune a bass with harmonics?#
You tune a bass with harmonics by comparing an open string with its octave harmonic, the note an octave above it. The 12th-fret harmonic sounds one octave higher than the open string, so it gives you a clearer pitch to check against on low strings.
- Press Start microphone and allow access when the browser asks.
- Choose your Tuning, such as 4-string standard (EADG).
- Lightly touch the string over the 12th fret, pluck it, and lift your finger straight away to sound the harmonic.
- The harmonic is the same note name one octave above the open string, so the tuner reads it more easily. Turn the peg until the needle is centred on that note.
- Pluck the open string again at medium strength and check that it also reads In tune.