How to use
Standard ukulele tuning
Standard tuning is G–C–E–A (4th to 1st string). The tuner auto-detects which string you're playing — just pluck and watch the needle.
Needle in the center = in tune
When the needle points straight up and the display turns green, your string is in tune. Flat (♭) means loosen, sharp (♯) means tighten.
Tips for accurate reading
Quiet room, pluck cleanly, hold the note. Keep your device close to the soundhole. New strings go flat quickly — retune after each string.
Does it work on mobile?
Yes. Works in Chrome and Safari on iPhone, Android, and desktop. Allow microphone access when prompted — audio never leaves your device.
About ukulele tuning
Standard GCEA tuning explained
Standard ukulele tuning is G–C–E–A, read from the 4th string (closest to your chin) to the 1st string (closest to the floor). The notes correspond to G4, C4, E4, and A4 in scientific pitch notation. This tuning has been the universal standard for soprano, concert, and tenor ukuleles since the early 20th century and is assumed by virtually all chord charts, tabs, and songbooks. If you pick up a ukulele and someone says "play a C chord", they're assuming GCEA tuning.
High G vs. low G — what's the difference?
Standard GCEA tuning uses a high G string — meaning the G string is tuned higher than the C string, which creates the characteristic re-entrant tuning sound of the ukulele. Low G tuning replaces the high G string with a wound string tuned an octave lower (G3 instead of G4), giving the instrument a wider range and a fuller, more guitar-like sound. Most beginners start with high G. Low G is popular among fingerstyle players and those who want more bass presence. This tuner supports both — it will detect whichever G string you're playing.
How often should you tune a ukulele?
Tune your ukulele every time you pick it up. Ukulele strings — especially nylon strings — are sensitive to temperature and humidity changes, which cause them to expand or contract and go out of tune. New strings are particularly unstable and may need retuning several times during a single playing session until they stretch and settle. As a rule of thumb: if you haven't played for more than a day, retune before playing. If you're performing live, check your tuning before every set and between songs if possible.
How does an online tuner work?
This tuner uses your device's microphone and the Web Audio API built into modern browsers to capture sound in real time. An autocorrelation algorithm analyses the audio waveform to detect the fundamental frequency (pitch) of the note you're playing. It then compares that frequency to the target frequency of each GCEA string and calculates the offset in cents — hundredths of a semitone. The entire process runs locally in your browser: no audio data is ever sent to a server. One cent equals 1/100th of a semitone. An offset of ±5 cents is generally considered in tune for casual playing; professional musicians often aim for ±2 cents.
Why does my ukulele go out of tune so quickly?
Several factors cause ukuleles to lose tuning faster than other instruments. Nylon strings (used on most soprano and concert ukuleles) are especially elastic and take time to stretch and stabilize — new strings can go noticeably flat within minutes of playing. Temperature changes cause the neck wood to expand and contract, shifting string tension. High humidity softens the wood and affects the neck angle. Cheap tuning pegs with worn friction also slip under string tension. If your ukulele constantly goes flat, try stretching new strings by gently pulling them away from the fretboard a few times after tuning. This speeds up the break-in period significantly.