Tune a guitar, bass, ukulele or violin with your microphone or by ear. The tuner shows the note and how many cents sharp or flat you are, all analysed in your browser and nothing recorded or sent anywhere.
Online Guitar Tuner (Chromatic Tuner)
Tune a guitar, bass, ukulele or violin with your microphone or by ear. The tuner shows the note and how many cents sharp or flat you are, all analysed in your browser and nothing recorded or sent anywhere.
The microphone signal is analysed on your device as it arrives and is never recorded, stored or uploaded. Your instrument, tuning, A4 reference and sensitivity are remembered in this browser only.
The Online Guitar Tuner works two ways. Press Start microphone, pluck a string and let it ring: the tuner measures how often the sound wave repeats, picks the nearest string and shows the note, its frequency in hertz and your offset in cents on a dial from minus 50 to plus 50, with a green band for anything within 5 cents. Or tap a string to lock the dial to it and hear a sustained reference note to tune by ear, no microphone needed. Presets cover guitar in seven tunings, bass, ukulele, violin, viola, cello, banjo and mandolin, and Chromatic mode names any note you play. A4 can be moved from 415 to 466 Hz. The sound is analysed on your device as it arrives and is never recorded or sent anywhere.
Features
Microphone tuning that picks the nearest string and shows the note, frequency in hertz and offset in cents
A dial from minus 50 to plus 50 cents with a green in-tune band within 5 cents and a needle steadied over several readings
Tune by ear: tap a string to hear a sustained reference note, tap it again to stop
Guitar in seven tunings: standard, drop D, DADGAD, open G, open D, half step down and whole step down
Presets for 4-string and 5-string bass, ukulele (standard and baritone), violin, viola, cello, banjo and mandolin
Chromatic mode that names whatever note you play, spelled with sharps or flats
An A4 reference from 415 to 466 Hz in 1 Hz steps, for 432 Hz, 442 Hz or baroque pitch
An input level meter and a sensitivity slider that stops a noisy room from moving the needle
How to use the Guitar Tuner
Choose your instrument and tuning, and move the A4 reference if you do not tune to 440 Hz
Press Start microphone and allow access when your browser asks
Pluck one string and let it ring; the dial shows how far it is from the note
Turn the peg until the needle rests in the green band, tuning up to the note rather than down
Or tap a string to hear its reference note and match it by ear
Example
Input
Guitar · Standard (E A D G B E) · A4 = 440 Hz
Pluck the low E string
Output
E2 · 81.8 Hz · −12.0 cents (flat) → Tune up ↑
Tighten the string slightly…
E2 · 82.4 Hz · 0.0 cents → In tune ✓
The dial measures against the nearest string: the needle sits left of centre while the string is flat, and the Status box says which way to turn the peg.
Common errors & troubleshooting
The needle jumps around and never settles. — Pluck one string at a time, let it ring and keep the room quiet. Lower the sensitivity if a fan or music is moving the needle, and move closer to the guitar.
Nothing happens when I press Start microphone. — Allow microphone access from the icon in the address bar when the browser asks, and check that the right input is chosen in your system sound settings. A page opened over plain http cannot use the microphone.
The tuner shows the neighbouring string instead of the one I am tuning. — In Auto mode it picks the nearest string, so a very slack string can look like the next one. Tap the string you are tuning to lock the dial to it.
The string is in tune, then drifts flat a minute later. — New strings stretch for days. Tune up to the note, pull the string gently along its length, then retune a few times; tuning down to a note leaves slack that lets it creep.
Frequently asked questions
How does the Online Guitar Tuner hear the note I play?
When you press Start microphone your browser asks for permission and then hands the sound to the page. About 25 times a second the tuner measures how often the sound wave repeats, which is the pitch, and steadies the result so one stray reading cannot move the needle. The audio is analysed on your device as it arrives. It is not recorded, stored or sent anywhere, and the microphone is released as soon as you press Stop or leave the page.
What notes and frequencies does the Online Guitar Tuner use for standard guitar tuning?
From the thickest string to the thinnest: E2 82.41 Hz, A2 110.00 Hz, D3 146.83 Hz, G3 196.00 Hz, B3 246.94 Hz and E4 329.63 Hz, with A4 at 440 Hz. Other tunings are in the Tuning list; drop D lowers the sixth string to D2, 73.42 Hz, and half step down lowers every string by 100 cents.
Why does the needle in the Online Guitar Tuner keep jumping?
Usually more than one sound is reaching the microphone: another string ringing, a fan, a voice or music. Pluck one string, mute the others with your hand and move closer to the guitar or amp. The sensitivity slider sets how loud a sound must be to count, so lower it in a noisy room and raise it for a quiet instrument. The first instant after a pick is also unstable, so the tuner waits for a few agreeing readings before it shows a note.
Can the Online Guitar Tuner tune a ukulele, bass or violin?
Yes. Choose the instrument and the tuner offers its usual tunings: ukulele GCEA with the high re-entrant G, and baritone DGBE; 4-string and 5-string bass; violin GDAE; viola and cello CGDA; five-string banjo in open G; and mandolin GDAE. Bass and cello use a longer listening window so the lowest notes are read correctly. For anything else, switch to Chromatic and it names whatever note you play.
What does setting A4 to 432 Hz change in the Online Guitar Tuner?
A4 is the reference every other note is measured from. At 440 Hz the A2 string is 110.00 Hz; at 432 Hz the whole scale moves down by about 32 cents, so A2 becomes 108.00 Hz and the dial reads zero there. Use 415 Hz for baroque instruments or 442 Hz for orchestras that tune a little sharp. Your choice is remembered in this browser.
Should I tune up to the note or down to it with the Online Guitar Tuner?
Tune up. If a string is sharp, turn the peg down a little below the note and then bring it up to the note, so the string settles under tension and stays in tune. The Status box says Tune down for a sharp string; go slightly under the note and approach it from below.
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More Music tools
Virtual Piano — Play a piano keyboard with mouse, touch or computer keys, with sustain, several sounds, recording and MIDI export.
BPM Counter — Tap a beat to find its BPM, or analyze an audio file to detect the tempo of a song.
Tone Generator — Generate sine, square, sawtooth and triangle tones from 1 Hz to 20 kHz, with sweeps and left or right channel control.
Metronome — A steady click from 20 to 300 BPM with time signatures, subdivisions, accents and tap tempo.