Free Online Bass Tuner
Tune your bass guitar instantly with our free online bass tuner. Supports 4, 5, and 6-string basses with 9 tunings, optimized for low-frequency accuracy. Zero downloads, zero sign-ups.
Bass Tuner
Free - Microphone - A440 - FFT 8192
Why Use This Bass Tuner?
Most chromatic tuners struggle with bass frequencies. A standard guitar tuner uses a 4096-point FFT, which gives roughly 10 Hz frequency resolution at 44.1 kHz. That is fine for guitar, but too coarse for bass notes below 50 Hz. This tuner uses FFT 8192 for double the resolution, a lower noise threshold, and a minimum sample size of 128 to reliably detect pitches all the way down to low A (27.5 Hz) on a 5-string bass in Drop A tuning.
| Feature | This Bass Tuner | Generic Tuner |
|---|---|---|
| FFT Size | 8192 | 2048–4096 |
| Low B Detection (30.87 Hz) | ✓ Reliable | Unreliable |
| Bass-Specific Tunings | 9 built-in | 0–1 |
| 5-String & 6-String | ✓ Full support | Rarely |
| Reference Tone | Sine wave (clean) | Square/Triangle |
| Cost | Free | Free–$30 |
How to Tune Your Bass Guitar
- Click “Start Tuner” and allow microphone access. No audio is recorded.
- Select your tuning from the dropdown. 4-String Standard (EADG) is the default.
- Pluck the lowest string firmly. Bass strings produce quieter fundamentals than guitar strings, so pluck with intention and let it ring.
- Watch the gauge. The needle will settle on your pitch. If it reads flat (needle left), tighten the peg. If sharp (needle right), loosen it.
- Tune from lowest to highest. E → A → D → G (or B → E → A → D → G for 5-string).
- Double-check after tuning all strings. The neck tension changes affect tuning stability, especially on short-scale basses.
4-String vs 5-String vs 6-String Bass
4-String Bass (EADG)
The standard configuration. E1 (41.2 Hz) to G2 (98 Hz). Covers 90% of bass music from rock and pop to funk and blues. Start here if you are a beginner. Drop D and Drop C variants are included for heavier genres.
5-String Bass (BEADG / EADGC)
The low-B 5-string (BEADG) adds range below the E string, reaching B0 (30.87 Hz). Essential for metal, gospel, modern worship, and modern pop. The high-C variant (EADGC) sacrifices low end for extended melodic range, popular with solo bass players and jazz.
6-String Bass (BEADGC)
Combines the low B and high C for maximum range. Covers B0 (30.87 Hz) to C3 (130.81 Hz). Used by progressive players, fusion artists, and solo bassists who need both deep grooves and chordal/melodic playing.
Common Bass Tuning Problems & Solutions
Tuner can't detect the low B string
Low B (30.87 Hz) is near the bottom of what microphones can pick up. Pluck the string firmly near the bridge for a stronger fundamental. Move closer to the microphone and mute other strings. If it still struggles, play the 12th fret harmonic to get the octave (61.7 Hz), then tune the open string by ear.
Dead spots where notes choke out
Dead spots are caused by neck resonance canceling specific frequencies. They are most common on the G string around the 5th–7th fret on Fender-style basses. A headstock weight (Fatfinger) can shift the dead spot. This is a physical issue, not a tuning issue.
Strings buzz after tuning down
Lower tunings reduce string tension, which can cause fret buzz. If you tune to Drop C or lower regularly, consider heavier gauge strings (e.g., .105-.050 or heavier). You may also need a truss rod adjustment for the reduced tension. Consult a tech if unsure.
Intonation is off on higher frets
If the open string is in tune but fretted notes at the 12th fret are sharp or flat, your saddle position needs adjustment. Most bass bridges have individual saddle screws. Move the saddle back if the 12th fret reads sharp, forward if flat.
Who Is This Bass Tuner For?
- Bass beginners - Learning your first bass lines and need a reliable, free way to stay in tune.
- Gigging bass players - Quick backup tuner on your phone when your pedal tuner fails.
- Producers - Laying down bass DI tracks at home. Use our MPC Drum Machine and Metronome to build full grooves.
- Metal and heavy rock players - Need Drop C and Drop D tunings without switching apps.
- 5-string and 6-string players - Most online tuners top out at 4-string. This one supports all three configurations.
- Guitar players - Looking to tune a guitar instead? Check out our dedicated Guitar Tuner with 12 alternate guitar tunings.
Frequently Asked Questions
Is this online bass tuner really free?+
Yes. This bass tuner is 100% free with no sign-up, no ads blocking the interface, and no feature limits. It runs entirely in your browser using the Web Audio API.
How accurate is this tuner for bass frequencies?+
This tuner uses an 8192-point FFT (double the standard size) for precise low-frequency detection. It can accurately detect pitches as low as 27.5 Hz (the low A on a 5-string bass in Drop A). Accuracy is within ±1 cent.
What bass tunings are available?+
This tuner supports 9 tunings: 4-String Standard (EADG), 4-String Drop D, Drop C, Half Step Down, Full Step Down (DGCF), 5-String Standard (BEADG), 5-String Drop A, 5-String High C (EADGC), and 6-String Standard (BEADGC).
Can I use this for a 5-string bass?+
Yes. Select "5-String Standard (BEADG)" from the dropdown to tune a 5-string bass. The low B string (30.87 Hz) is fully supported with the extended FFT window.
Why can't the tuner detect my low B string?+
Low B (30.87 Hz) requires a very clean signal. Make sure you are in a quiet room, pluck the string firmly with your finger or a pick, and hold your device close to the speaker or pickup. Background noise and harmonics can confuse the detector at these extreme low frequencies.
Does this work with active and passive pickups?+
This tuner uses your device's microphone, so it works regardless of pickup type. Simply pluck the string and let the microphone pick up the sound. For the cleanest signal, tune acoustically rather than through an amplifier, which can color the tone.
What is the difference between 4-string and 5-string bass?+
A 4-string bass has strings EADG. A 5-string bass adds a low B string below the E (BEADG), giving you deeper range for genres like metal, gospel, and modern pop. Some 5-string basses use a high C instead (EADGC) for more melody range.
What is Drop D tuning on bass?+
Drop D lowers the 4th string (lowest) from E to D. This gives you a deeper low end and lets you play power-chord root-fifth shapes with one finger. It is widely used in rock, metal, punk, and alternative bass lines.
Can I hear a reference tone for each string?+
Yes. Tap any string in the string panel to hear its reference pitch. The tuner plays a clean sine wave tone, which provides the purest fundamental for matching bass notes by ear.
Does this work on mobile phones?+
Yes. The tuner works on iOS and Android devices in Chrome, Safari, and Firefox. Bass frequencies need a clear signal, so hold your phone near the instrument in a quiet room for best results.
Why does my bass go out of tune quickly?+
Common reasons include old strings (bass strings deaden faster than guitar strings), temperature or humidity changes, an improperly cut nut, or unstable tuning machines. New roundwound strings can take 1-2 days of playing to fully stretch and stabilize.
What is intonation and how does it affect tuning?+
Intonation is whether fretted notes are in tune relative to the open string. If your open string is perfectly tuned but the 12th fret harmonic is sharp or flat, your intonation needs adjustment. On most basses, this is done by adjusting the saddle position on the bridge.