Jam JamFree online bass tuner
A bass tuner that hears the low E at 41 Hz — standard, drop D and half-step down, right in your browser.
The Jam Jam bass tuner listens through your microphone and tells you, string by string, whether you are sharp or flat. Three 4-string tunings are ready: standard G D A E, drop D and half-step down. The hard part on a bass is the low end — the bottom E sits at 41 Hz, the drop D at 37 Hz. Jam Jam works out a detection band matched to the instrument, reaching down to 30 Hz, and reads pitch with YIN over 4096-sample frames: long enough to lock onto a fundamental that low instead of grabbing its harmonic and showing the octave above. No download, no account. And your bass lines are waiting in the notebook, as tablature read in that very tuning.
How to tune a bass online
Allow the microphone
Open the tuner, pick Bass and grant mic access. Jam Jam asks for a raw signal: no noise suppression, no auto gain.
Pick your tuning
Standard G D A E, drop D to take the bottom string down, or half-step down — the four target notes appear at once.
Play one open string
Pluck a single string near the bridge and let it ring. The nearest string locks on its own; a tap freezes it.
Centre the needle
Turn the tuning key until the needle is centred and green: you are inside ±5 cents of the target note.
Built for the low end
It hears 41 Hz — and 37 Hz
The detection band is computed for the instrument and goes down to 30 Hz, so the low E and the drop D read as themselves, not as the octave above.
YIN over 4096-sample frames
A long analysis window is exactly what a 41 Hz fundamental needs; a shorter one grabs a harmonic and announces the wrong string.
Raw microphone, on purpose
Noise suppression and automatic gain are asked to stay off: on bass frequencies they crush precisely what has to be measured.
Reference note in a bass voice
Each string plays its target note with the timbre of a bass, not a piano ping — far easier to match by ear an octave down.
Why this bass tuner
- 3 bass tunings: standard, drop D, half-step down
- Cents to the unit, frequency to 0.1 Hz, green inside ±5 cents
- Automatic string lock, or tap to hold one string
- Free in your browser, no sign-up — offline in the Android app
A bass is where cheap tuners give up: the fundamental is quiet, the harmonics are loud, and the needle ends up an octave too high. Jam Jam cuts its detection band to fit the instrument, down to 30 Hz, and shows cents to the unit next to the frequency to a tenth of a Hz — you can see the gap between 41.2 Hz and 41.9 Hz. And the tuner is only one tab: your bass tablature plays back in the same tuning, bass chord diagrams run to the 20th fret, and the chords of the song land in the same notebook.
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Guides & tips
Short, no-nonsense guides to play, tune and find chords faster — each one backed by a Jam Jam tool you can open right away.
Bass tuner FAQ
Is this bass tuner free?
Yes — free, no sign-up, no ads. It all happens in your browser and nothing you play is uploaded: the pitch is computed on your device. The Android app tunes offline as well.
Does it handle drop D and half-step down?
Yes. Three 4-string tunings are built in: standard G D A E, drop D (G D A D) and half-step down (Gb Db Ab Eb). For a 5-string or anything else, chromatic mode names every note from 40 to 1600 Hz.
Why do other tuners show the wrong octave on my low E?
Because a 41 Hz fundamental is weaker than its harmonics, and a short analysis window latches onto one of them. Jam Jam uses YIN over 4096-sample frames and a band reaching 30 Hz, so the low E reads as an E.