Play a string and watch the needle. Pick your instrument for string-by-string targets, or use chromatic mode for anything. Cents-accurate, with an adjustable A4 — and the mic never leaves your device.
How it works
Choose guitar, bass, ukulele, violin, or cello for string targets, or stay on Chromatic to tune single notes on anything — including odd tunings and wind instruments.
Your browser asks for microphone access once. Play a string cleanly and let it ring — the tool shows the note and how many cents flat or sharp you are.
Turn the peg until the needle sits on the green centre line and the read-out says "In tune". Repeat for each string.
Who uses it
Five moments when a tuner in the browser tab beats hunting for an app.
The situation: You want to play for ten minutes and your clip-on tuner has a dead battery.
What they do: Open the tab, pick Guitar, and tune all six strings by ear against the needle.
The result: You are in tune and playing without leaving your seat.
The situation: You are about to record or perform and want to confirm the tuning is dead on.
What they do: Nudge the A4 reference to match the track or the piano, then check each string to the cent.
The result: The instrument sits right in the mix instead of a few cents off.
The situation: A beginner is not sure whether a string is sharp or flat.
What they do: Watch the needle and the flat/sharp label while slowly turning the peg to see which way it moves.
The result: The connection between turning the peg and the pitch finally clicks.
The situation: A recording or ensemble is tuned to A4 = 442 rather than 440.
What they do: Set the reference pitch to 442 and tune every string against it.
The result: Your instrument matches the session without doing the maths in your head.
The situation: You need clean fifths across all four strings before a lesson or rehearsal.
What they do: Select Violin or Cello and tune each string to its target, checking the cents as you go.
The result: The open strings ring in tune and the intonation problems start smaller.
FAQ
No. The audio is analysed live in your browser and thrown away frame by frame. Nothing is recorded, saved, or uploaded.
It reads pitch to within a couple of cents on a clean, sustained note. Background noise, a buzzing string, or a very short pluck will make the needle jump around — let the note ring.
A cent is one hundredth of a semitone. Musicians usually consider anything within about 5 cents of centre to be in tune, which is where the read-out switches to green.
It sets the pitch of the note A above middle C, normally 440 Hz. Change it to 442 or 415 to match an orchestra, an old piano, or a period-instrument ensemble.
Yes. There are Drop D and half-step-down guitar presets, and Chromatic mode handles any tuning — it just names whatever note it hears.
Usually the string is not ringing cleanly, another string is vibrating, or the room is noisy. Mute the other strings, play one clean note, and hold it.
Yes, in Chromatic mode. Play and hold a steady note and tune to the needle the same way.
Yes, in a modern mobile browser. Allow microphone access when asked and hold the phone near the instrument.
Check that the site has microphone permission in your browser settings and that no other app is using the mic, then reload and press Start again.
Yes, completely, with no account, no ads in the tuner, and no usage limit.