Tuner
This page listens through your microphone and describes what it hears in plain words: the name of the closest note, and how far the sound is from that note.
Before you start
You need a microphone; the one built into a laptop or phone works well. The first time you press Start tuner, the browser asks for permission with its own dialog: choose Allow. Play one string at a time and let each note ring while you turn its peg. A quiet room helps, but unpitched sounds such as talking or fan noise are ignored rather than misread. Keep the guitar close to the microphone: an electric guitar played without an amplifier is quiet, so a hand's width from a laptop microphone works much better than across the room, and plugging into an amplifier at low volume works too.
Privacy
The sound is analyzed inside your browser in the moment it is heard. Nothing is recorded, nothing is stored, and nothing is sent anywhere; this site has no server and loads no external code. Pressing Stop tuner, or leaving this page, releases the microphone completely, and your device's microphone indicator turns off with it.
How the readings work
A full reading names the closest note, then gives the verdict, for example: E. About 20 cents too low. Tune higher. Too low means the pitch must come higher; too high means it must come lower. A cent is one hundredth of a semitone, readings round to the nearest five cents, and within five cents the tuner simply says: In tune. Readings use A at 440 hertz.
The note name is spoken when it changes and skipped while you keep working on the same string, so a session sounds like: E. About 20 cents too low. Tune higher. Then: About 10 cents too low. Tune higher. Then: In tune. After a few seconds of silence the name returns with the next reading, so you always know where you are.
The tuner speaks only when a note has settled and the reading has changed, stays silent while nothing is playing, and never says the same thing twice in a row. The Mute announcements button stops all automatic speech; the current reading stays on the page as plain text, for you to read whenever you choose.
The tuner does not try to work out which string you played; it names whichever note sits closest to the pitch it hears. Every E on the guitar, from the thickest string to the thinnest, reads simply as E, and a note with two names is given both, for example: F sharp or G flat. The verdicts always steer toward that closest note, not toward the note you are aiming for. So if the tuner names a note lower than the one you want, keep tuning higher until the name you expect arrives; if it names a note higher than your target, keep tuning lower. Once the right name appears, follow the verdicts to: In tune. The string naming choice on the Settings page shapes chord and fretboard descriptions; tuner readings name notes the same way for everyone.