Bass Tuner Online

The bass tuner covers standard four-string tuning (E1 A1 D2 G2) and common alternative tunings including Drop D (D A D G), Eb standard, and five-string bass (B E A D G). The low frequencies of bass strings are well within the tuner's detection range.

Low-frequency strings produce fundamental pitches that some built-in microphones capture less clearly than mid-range guitar notes. To improve detection, play the string firmly, hold the device within 20–30 cm of the bass body, and avoid very noisy environments. Plugging into an amp at a moderate volume can also help if detection is inconsistent.

No app is needed. TuneUniversal is a fully browser-based tuner that works on any device with a microphone and an up-to-date browser. There is nothing to install or update — just open the page and start tuning.

Yes. The tuner detects pitch from the microphone regardless of whether your bass is passive or active. If you use an audio interface with your computer, the tuner can also pick up the signal through the interface microphone input.

Select the five-string preset if available, or tune each string manually by identifying the note shown on screen. The low B string (B0) sits just below E1 on the chromatic scale. Play it slowly and firmly — the very low frequency may take a moment longer for the browser to detect reliably.

Standard four-string bass tuning is E1 A1 D2 G2, reading from the lowest to highest string. These are the same note names as the four lowest strings on a guitar, but an octave lower. Five-string basses add a low B1 string below the E, and six-string basses add both a low B and a high C above the G.

The tuner needle should center on the target note with 0 cents shown — on TuneUniversal the display turns green. Beyond the visual signal, trust your ears. Play the open A string against the A at the fifth fret of the low E: if they produce a wavering beat, they are not quite at unison. No beats means perfect unison and confirms both strings are in tune relative to each other.

Yes. A fretless bass produces the same fundamental pitches as a fretted bass — the tuner detects the open string note regardless of whether there are frets. The key difference is that intonation on a fretless bass also depends on your left-hand finger placement, which the tuner cannot assess. Use the tuner for open string tuning, then verify intonation by comparing harmonics at the 12th position with the stopped note at that point.

This is an intonation problem, not a tuning problem. Intonation refers to whether fretted notes are in tune along the full length of the neck. If the open strings are correctly tuned but the 12th fret sounds sharp or flat, the bridge saddle needs adjustment. This is a mechanical fix — not something a tuner alone can resolve. A local guitar technician can set intonation in a few minutes with a screwdriver.

Enable the microphone, pluck one string clearly and wait a second for the needle to settle, then adjust toward the centre.

Standard 4-string bass tuning is E1 A1 D2 G2, from lowest to highest string.