Tuner, in your browser.
Press Start, allow the microphone, and play one note. It shows the note and says which way to turn the peg.
Free · runs in your browser · no sign-upPress Start, then play a note
The tuner asks for the microphone. Nothing is recorded or sent.
How to use it
- Press Start tuner and allow the microphone. Nothing is recorded or sent; the pitch is worked out in your browser.
- Play one string and let it ring, close to the phone or laptop.
- Read the note and the word: Too low · tighten or Too high · loosen. Turn the peg slowly until it says In tune (within 5 cents).
Tune up to the note, not down to it: if you go past, loosen a little below the note and come back up. The string then holds its tuning better.
Standard tunings (A = 440 Hz)
| Instrument | Strings, low to high | Frequencies (Hz) |
|---|---|---|
| Guitar | E2 A2 D3 G3 B3 E4 | 82.4 · 110.0 · 146.8 · 196.0 · 246.9 · 329.6 |
| Guitar, Drop D | D2 A2 D3 G3 B3 E4 | 73.4 · 110.0 · 146.8 · 196.0 · 246.9 · 329.6 |
| Ukulele | G4 C4 E4 A4 | 392.0 · 261.6 · 329.6 · 440.0 |
| Violin | G3 D4 A4 E5 | 196.0 · 293.7 · 440.0 · 659.3 |
| Viola | C3 G3 D4 A4 | 130.8 · 196.0 · 293.7 · 440.0 |
| Cello | C2 G2 D3 A3 | 65.4 · 98.0 · 146.8 · 220.0 |
The number after the note is the octave: E2 is the low E of a guitar, A4 is the A above middle C. Ukulele G4 is higher than C4 on purpose (re-entrant tuning).
Cents, in one paragraph
A cent is one hundredth of a semitone. Most people cannot hear a difference of less than about 5 cents on a single note, which is why the tuner calls anything within ±5 cents in tune. Two strings that are each 5 cents out the other way are 10 cents apart, and that you can hear as a slow beat when you play them together.
What the app adds
The Metronome & Tuner app has the same plain words, plus tunings for guitar, bass, ukulele, violin, viola, cello, mandolin and banjo (Drop D and more), string keys, a reference pitch from 415 to 466 Hz, and a page with the tuner and the metronome together for orchestra, band and choir. In our tests with clean test tones from 31 Hz to 1.5 kHz it read within 1 cent. It works offline, and it uses the microphone only while the tuner is on screen.
Questions
Is this online tuner free?
Yes. No account, no ads, nothing to install.
Does it record me?
No. The page reads the microphone in your browser to find the pitch, and keeps nothing. No sound is saved or sent anywhere. It turns the microphone off when you press Stop or leave the tab.
Which instruments can I tune?
Any instrument that holds a steady note from about 60 Hz to 1,400 Hz: guitar, ukulele, violin, viola, cello, mandolin, voice, wind instruments. The tables on this page list the standard tunings. For a bass guitar, tune with the harmonic at the 12th fret, which is one octave higher.
What do “tighten” and “loosen” mean?
On a string instrument, a note that is too low needs more tension: turn the peg to tighten the string. A note that is too high needs less: loosen it. On a wind instrument, push the tuning slide in to go higher, out to go lower.
What is A = 440 Hz?
The pitch of the A above middle C. Most music today uses 440 Hz. Some orchestras tune to 442 Hz, and some people prefer 432 Hz. Choose it before you tune.
Why does the note jump around?
The first moment of a plucked note is noisy. Play the note and let it ring, close to the phone or laptop, in a quiet room. Pluck with the soft part of your thumb, not a pick, for low strings.