Free Online Guitar Tuner & Instrument Tuner_
INSTRUMENT
Guide — in tune in about a minute
Choose a tuning from the INSTRUMENT list, such as Guitar Standard, Drop D, Bass or Ukulele. Pick Chromatic to tune to any note.
Press START TUNER or Space and allow microphone access. The sound is analysed in your browser and never uploaded.
Pluck a single string and let it ring. The tuner finds the nearest string, highlights it and shows how many cents off you are.
Flat means tune up, sharp means tune down. Stop when the needle sits in the green zone and the strobe stands still.
Hold a string in tune for about a second and it gets a ✓. The counter shows how many strings are done.
What is in here
The big readout shows the note, the frequency you play and the target frequency. Below it, a needle, a strobe and a history graph show the same error in different ways, so you can pick the one that suits you.
- Needle
- −50 to +50 cents, green zone at ±5 cents
- Strobe
- Drifts right when sharp, left when flat, freezes when in tune
- History
- Your pitch over the last 8 seconds, ±50 cents
- Readout
- Note, Hz, target Hz and cents, with “tune up” or “tune down”
Each preset lists its strings with their target frequency. The tuner snaps to the nearest string in the tuning, so you can tune them in any order.
- Guitar
- Standard, Drop D, Half-step down, DADGAD, Open G, Open D, 7-string, 12-string
- Bass
- 4-string (E A D G) and 5-string (B E A D G)
- Fretted
- Ukulele, Baritone ukulele, Mandolin, 5-string banjo in open G
- Bowed
- Violin, Viola, Cello
- Chromatic
- Nearest of all 12 notes, for any instrument
Open the TONE tab for a four-octave keyboard. Tap a note and it keeps playing until you tap it again. Or click a string in the tuner panel to hear its reference note.
- Range
- C2 to B5
- Waves
- Sine, triangle, square, organ
- Organ
- Adds harmonics, so low notes are audible on small speakers
- String button
- Plays that string’s note for two seconds
Both the tuner targets and the tone generator follow the A4 reference. The gate decides how loud a sound must be before the tuner reacts.
- A4
- 415 to 466 Hz, default 440 Hz
- Presets
- 432 · 440 · 442
- GATE
- Raise it if noise triggers the tuner, lower it if quiet notes are missed
- Remembered
- Your instrument and A4 setting stay saved in this browser
Fullscreen hides everything except the tuner and makes the note bigger, which helps when your phone sits on a music stand.
- Space
- Start or stop the tuner
- F
- Fullscreen on and off
- Esc
- Leave fullscreen
- Wake lock
- The screen stays on while the tuner listens
A free online guitar tuner and chromatic tuner in your browser
This free online guitar tuner listens through your microphone and tells you which note you are playing and how far off it is. It is also a full chromatic instrument tuner, with presets for bass, ukulele, mandolin, banjo, violin, viola and cello. There is nothing to download and no account. It works in any modern browser on a laptop, desktop, phone or tablet, and it is free with no time limit.
How the tuner works
Press START TUNER and allow microphone access. The page reads the sound with the Web Audio API and finds its pitch with the YIN pitch-detection algorithm. Parabolic interpolation refines the result between samples and a short median filter smooths out jumps, so the reading resolves to about ±1 cent on a clean, sustained note.
A cent is 1/100 of a semitone. Most people cannot hear an error below about 5 cents, which is why the green in-tune zone on the needle is ±5 cents. If you want to chase the last cent, watch the strobe: the stripes move in the direction of your error and move faster the further off you are. When they stop moving, you are in tune. That is the same idea professional strobe tuners use.
The pitch history graph draws the last 8 seconds of your pitch. You can see a note start slightly sharp when you pluck it and then settle, and you can spot a tuning peg that slowly slips or a new string that still needs stretching.
Standard guitar tuning and alternate tunings
Standard tuning on a six-string guitar is E2 A2 D3 G3 B3 E4, from the thickest string to the thinnest. At A4 = 440 Hz the low E string is 82.41 Hz and the high E is 329.63 Hz. Select the Guitar Standard preset and the tuner snaps to the nearest of those six strings, checks each one off and counts how many are done.
The other guitar presets cover the tunings people search for most:
- Drop D (D A D G B E): the low E string drops a whole step to D.
- Half-step down (E♭ tuning): every string a semitone lower.
- DADGAD, Open G (D G D G B D) and Open D (D A D F♯ A D) for folk, slide and fingerstyle playing.
- 7-string (B E A D G B E) with the extra low B.
- 12-string: the four lower courses (E A D G) pair a normal string with one an octave higher, and the B and E courses are tuned in unison. Tune the main string of each course with the preset first, then switch to Chromatic to tune the octave strings to E3, A3, D4 and G4.
Bass, ukulele, violin and other instruments
The bass tuner presets cover 4-string (E A D G) and 5-string (B E A D G) bass. The ukulele tuner uses G C E A, and the baritone ukulele D G B E. Mandolin and violin are both G D A E, viola and cello are C G D A, and the 5-string banjo is set to open G. For anything else that plays a clear, sustained note, such as a voice, a wind instrument or a piano string, choose Chromatic and the tuner shows the nearest of all 12 notes.
Tune by ear with the tone generator
Prefer to tune by ear? Switch to the TONE tab and tap any note from C2 to B5. It keeps sounding until you tap it again, so you can match your string against it. Choose sine, triangle, square or organ. The organ sound adds harmonics, which makes low notes much easier to hear on laptop and phone speakers. You can also click any string in the tuner panel to hear its target note for two seconds.
432 Hz, 440 Hz or 442 Hz
The tuner defaults to A4 = 440 Hz, the usual concert pitch. Move the A4 slider anywhere from 415 to 466 Hz, or tap the 432, 440 or 442 buttons. Many orchestras tune to 442 Hz, baroque ensembles often use 415 Hz, and some players like to try 432 Hz. The string targets and the tone generator both follow the reference you set, and the page remembers it next time.
When the tuner does not pick up your note
- Too quiet: play closer to the microphone or lower the GATE slider.
- Background noise: raise the gate so hum and chatter are ignored.
- Note has faded: a decaying note turns into mostly harmonics. Pluck once, moderately hard, and read the display while it rings.
- Several strings at once: the tuner follows one pitch at a time, so play single strings rather than a strummed chord.
Tuning on your phone
The tuner runs in mobile browsers too. Allow microphone access when asked. Press FULL for fullscreen; where the browser does not offer real fullscreen, such as Safari on iPhone, the tuner fills the page instead. While the tuner is listening, a wake lock keeps the screen from switching off in the middle of a tune-up.
Private: no audio is recorded or uploaded
All pitch detection happens locally in your browser. The microphone stream is analysed in real time and is never recorded, stored or sent to a server. You can check your browser's network tab: no audio is transmitted. The only things saved are your chosen instrument and A4 setting, in your own browser's local storage.
Keyboard shortcuts
Space start or stop the tuner · F fullscreen · Esc leave fullscreen.
More music tools
Once you are in tune, practise in time with the online metronome and BPM counter, look up chord shapes in the chord chart generator, or play along with a song in the song practice player. Program a beat to jam over in Drum Loop Studio, try the virtual piano, or play chords with your hands in Simple Hand Tracking Chords. All of them are listed on the music tools page.