Online Tuner — Free Chromatic Tuner for Guitar, Bass, Violin & More

What's inside

A real tuner, not a toy.

Chromatic detection, instrument presets, alternate tunings, a strobe view and drum targets — free, in the browser.

Chromatic, cents-accurate

Hears any pitched source — strings, voice, brass, winds — and shows the nearest note, the frequency in Hz and how far off you are in cents. Green at ±5¢.

Nine instrument presets

Guitar, bass, ukulele, violin, viola, cello, mandolin, banjo and drums. Pick one and the string strip lights up the string you are playing, so you tune to the right target every time.

Alternate & custom tunings

Drop D, E♭, open G, DADGAD, 5-string bass, low-G and baritone ukulele, banjo open G and double C — or type in your own tuning and it is saved to your account.

Strobe view

Switch the cents bar for a strobe display that drifts while you are off and freezes when you land. The classic way to hear the last cent.

Drum tuning targets

Kick, snare, rack and floor toms each get a fundamental-frequency range; hit the head and see where the drum sits inside it.

Metronome one tab away

The tuner is one half of BPM Forge: tap tempo, a metronome with count-in, per-song setlists and a delay calculator live in the other tab.

The real thing

This is the tuner you'll open.

Straight out of BPM Forge — the Tuner tab with the instrument and tuning pickers, the cents bar and the string strip.

The BPM Forge Tuner tab inside Squaresmile Tools: a large note readout above a cents bar, the Start tuner button, and instrument pills for Chromatic, Guitar, Bass, Ukulele, Violin, Viola, Cello, Mandolin, Banjo and Drums. — Pick an instrument, pick a tuning, press Start — the string strip lights up the string you are playing.

Presets

Every instrument, every common tuning.

Choose a preset and the tuner listens for those strings only — or stay chromatic and tune anything. Custom tunings are saved to your account.

Chromatic

Any note, any source — voice, brass, winds, piano. A = 440 Hz.

Guitar

Standard · Drop D · E♭ (½ down) · Open G · DADGAD · D A E A C♯ E · F A C G C E

Bass

Standard 4-string · 5-string (low B) · Drop D

Ukulele

Standard (high G) · Low G · Baritone

Violin

G3 · D4 · A4 · E5

Viola

C3 · G3 · D4 · A4

Cello

C2 · G2 · D3 · A3

Mandolin

G3 · D4 · A4 · E5

Banjo

Open G (5-string) · Double C

Drums

Kick · snare · hi, mid and low toms · floor tom — target ranges in Hz

Three steps

From open string to in tune in seconds.

01

Allow the microphone

Press Start and let the browser use your mic. Audio is analysed on your device; nothing is recorded or uploaded.

02

Play one note

Pluck a single string or hold one note and let it ring. The nearest note and the frequency appear at once.

03

Watch the needle

Left of centre is flat — tune up. Right is sharp — tune down. Green means you are within five cents.

Who tunes

Made for anyone with strings, skins or a voice.

Guitar & bass

Standard or drop tunings with a string strip that follows what you play — on stage, in the rehearsal room, or on the sofa.

Violin, viola & cello

Fifths-tuned presets and a strobe view for the last cent — the part an ear alone gets wrong after a long day.

Ukulele, mandolin & banjo

High-G, low-G and baritone uke, mandolin, and banjo open G or double C — no more hunting for the right app.

Singers & wind players

Chromatic mode hears any pitched sound, so you can check intonation on a long note or a whole phrase.

Drummers

Tune each drum into its fundamental range instead of guessing — kick, snare, toms and floor tom each have a target.

Music teachers

One shared browser tab for the whole class: tuner here, metronome and tap tempo in the tab next door.

Good to know

Frequently asked questions.

Is this online tuner free?

Yes. The chromatic tuner on this page runs without an account. The full tuner in BPM Forge — instrument presets, custom tunings, strobe view, in-tune chime and drum targets — is free too; it only asks for a free Squaresmile account so your tunings sync across devices.

Which instruments can I tune?

Anything pitched in chromatic mode. Presets cover guitar, bass, ukulele, violin, viola, cello, mandolin and banjo, each with its common tunings, plus drum tuning targets for kick, snare, toms and floor tom.

How accurate is it?

The detector is the same autocorrelation pitch tracker BPM Forge uses, referenced to A = 440 Hz, with the reading smoothed so the needle does not flicker. Deviation is shown in cents; you are counted as in tune inside ±5¢. For the final cent, use the strobe view in the app.

Does it upload my microphone audio?

No. Pitch is detected in your browser with the Web Audio API. Nothing is recorded, stored or sent anywhere — closing the tab or pressing Stop releases the microphone.

Why doesn't it hear my instrument?

Check that the browser was allowed to use the microphone (look for the mic icon in the address bar) and that the right input is selected. Play one clear note and let it ring — chords and heavy distortion confuse any tuner. On a phone, move away from fans and air conditioning.

Does it work on my phone?

Yes — iPhone and Android, in Safari and Chrome, with no app to install. BPM Forge is a phone-first tool and can be added to your home screen.

What about custom tunings and a strobe display?

Both live in the full tuner: open BPM Forge, switch to the Tuner tab, pick an instrument, choose a preset or type a custom tuning, and toggle the strobe view. Your choices are saved to your account.

Airchain

Online tuner.
Tune up right here.