Free online bass tuner for 4-string (E-A-D-G) and 5-string (B-E-A-D-G) standard tuning, optimised for low frequencies. Real-time pitch, frequency and cents from your microphone; audio stays in your browser.
How to tune: Bass
- Pick a tuning above (if unsure, keep the first, standard one).
- Press “Start tuning” and allow the microphone in the browser prompt.
- Play one string at a time close to the mic and wait for a steady reading.
- Needle left (flat): tighten. Needle right (sharp): loosen. The green zone means in tune.
On a 4-string bass start from the thickest string: 4th E1, 3rd A1, 2nd D2, 1st G2. A 5-string adds a lower 5th string, B0. Bass sits in a low register, so let the note ring and wait for the needle to settle: left means tighten, right means loosen.
Bass frequencies (A4 = 440 Hz)
| String | Note | Frequency (Hz) |
|---|---|---|
| String 4 | E1 | 41.20 |
| String 3 | A1 | 55.00 |
| String 2 | D2 | 73.42 |
| String 1 | G2 | 98.00 |
Bass tuning tips
Bass frequencies are low (E1 is about 41 Hz) and phone or laptop microphones are not sensitive down there. Move the body to within 10–20 cm of the microphone, or use an external mic or audio interface. Picking with even force gives a steadier reading. The 5-string B0 (about 31 Hz) is the hardest note to detect: tune strings 4 to 1 first, then do the 5th on its own.
Is microphone audio uploaded?
No. Web Audio analyzes sound in real time on your device. This page does not record, upload or store microphone audio.
Frequently asked questions
What is the difference between a 4-string and a 5-string bass?
A 5-string adds a B0 string on the low side; the other four are identical to a 4-string bass. Switch presets to change.
Why does the bass tuner react more slowly than the guitar tuner?
Low notes have long vibration periods, so the detector needs more samples. Moving closer and holding the note for two to three seconds helps a lot.
Can I tune a bass with a phone?
Yes, but phone microphones respond weakly below 40 Hz. Get close to the soundhole or pickup, or use a device with an audio interface.
Do I need an amp or effects pedal?
No. Playing acoustically or through the pickup is enough — an amp can actually add room noise.
