Chromatic Tuner Online
A chromatic tuner shows the nearest of all twelve notes, with its octave and how many cents you are off, instead of comparing with a fixed set of strings. Use it for alternate ukulele tunings, a bass ukulele’s upper notes, guitar, violin or your voice. Press Start, play one note and read the needle.
Chromatic tuner
The tuner needs JavaScript and a microphone. The tables and guides below work without it.
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Press Start tuner and allow the microphone
Reference pitch: A4 = 440 Hz
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Chrome on a computer
Click the icon to the left of the web address, find Microphone, choose Allow, then reload the page.
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Click the permissions icon in the address bar, remove the blocked microphone permission, reload the page and choose Allow when asked.
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Open Safari, Settings, Websites, Microphone, and set ukuleletuner.co to Allow or Ask. Then reload the page.
iPhone or iPad
Tap the page settings button in the address bar, open Website Settings and set Microphone to Allow or Ask. Then reload the page.
Chrome on Android
Tap the icon to the left of the web address, open Permissions, and turn on Microphone. Then reload the page.
Mic not working at all? Test it at testthemic.app.
How to use it
- Press Start tuner and allow the microphone.
- Play one note and let it ring.
- Read the note, the octave and the cents.
- Adjust until the display turns green.
When to use chromatic mode
- Alternate tunings: open tunings, slack tunings, or a tuning from a songbook that is not in the list.
- Other instruments: guitar, mandolin, violin and others, within the range the tuner listens to (about 70 to 1,200 Hz).
- Checking intonation: play the 12th fret and compare it with the open string. It should be the same note one octave higher.
- Singing: hold a steady note to see which note it is. For your full range, try the vocal range test.
Reading the display
The big letter is the nearest note, and the small number is the octave: C4 is middle C, A4 is the 440 Hz A. The needle and the cents number show how far from that note you are. Minus means too low, plus means too high. Within 5 cents the display turns green.
Notes with a sharp are shown with #. The same note can also be named with a flat: A# is the same pitch as Bb.
Range and limits
The tuner listens from about 70 Hz to 1,200 Hz. That covers every ukulele string, the guitar from its low E string (about 82 Hz) upward, and most voices. Very low notes such as a bass guitar’s E string (about 41 Hz) are below the range.
How the tuner hears a note
A plucked string vibrates at one main frequency, its pitch, plus weaker overtones. The tuner takes a short slice of sound from the microphone (about a tenth of a second), and uses the YIN method, a well-known pitch detection algorithm, to find how often the waveform repeats. Several readings in a row are combined so the needle does not jump.
The result is compared with the target note and shown in cents. A cent is a hundredth of a semitone, the step between two neighbouring frets. The tuner shows "In tune" within 5 cents of the target, which is closer than most people can hear.
Frequently asked questions
What is a chromatic tuner?
A chromatic tuner recognises all twelve notes of the scale and shows the nearest one, wherever you are. A ukulele tuner in string mode only compares with four target notes. Chromatic mode is better for unusual tunings and other instruments.
Can I tune a guitar with this tuner?
Yes. Standard guitar tuning is E2 A2 D3 G3 B3 E4. Play one string at a time and turn the peg until the tuner shows the right note in green. The low E is about 82 Hz, inside the tuner’s range.
What does the number after the note mean?
It is the octave. Middle C is C4, and the A above it, at 440 Hz, is A4. A ukulele’s standard G string is G4; a low G string is G3, one octave lower.
What is a cent?
A cent is one hundredth of a semitone. A semitone is the step from one fret to the next. Most people cannot hear a difference of less than about 5 cents, which is why the tuner shows In tune within that range.
Can I change the reference pitch?
Yes. Open Reference pitch and set A4 anywhere from 430 to 450 Hz. Use it only if your band or a recording is tuned to a different A. All notes shift with it.
Last updated: October 15, 2026