Online Chromatic Tuner
A free chromatic tuner that listens through your microphone and shows the detected note, octave, frequency in Hz and how many cents you are sharp or flat.
TuneStand needs microphone access to detect pitch. Audio is analysed on your device and never uploaded.
This chromatic tuner uses your microphone and an autocorrelation pitch-detection algorithm to work out the note you are playing. It shows the note name, the octave, the exact frequency in hertz and how many cents sharp or flat you are, so you can tune a guitar, violin, ukulele, brass or any other pitched instrument. Audio is analysed on your device and never leaves your browser.
How the tuner detects pitch
When you allow microphone access, TuneStand captures short windows of audio and runs an autocorrelation analysis on them. Autocorrelation slides a copy of the waveform against itself to find the repeating period of the sound; the inverse of that period is the fundamental frequency. This is a well established signal processing technique, not machine learning, and it is reliable for the sustained tones of a tuning instrument. The detected frequency is then compared against equal temperament with A4 fixed at 440 Hz to find the nearest note and the difference in cents.
A cent is one hundredth of a semitone. A reading of zero cents means you are perfectly in tune; a positive value means you are sharp and should loosen or lower the pitch, while a negative value means you are flat and should tighten or raise it. Aim to land within a few cents of centre for a clean, in-tune note.
Tuning common instruments
For a guitar in standard tuning, play each open string and match it to E2, A2, D3, G3, B3 and E4. A violin tunes to G3, D4, A4 and E5, while a ukulele in standard reentrant tuning uses G4, C4, E4 and A4. Play one note at a time, let it ring, and watch the needle settle. Muting the other strings gives the algorithm a cleaner signal to lock onto.
If the tuner cannot access your microphone, check that you granted permission and that no other app is holding the mic. On some browsers, microphone access requires a secure origin, so the tuner works best over HTTPS. When the mic is unavailable, the page shows a clear message and you can still use the tone generator and note frequency chart as tuning references by ear.
Frequently asked questions
Does the tuner send my audio anywhere?
No. Your microphone signal is analysed locally in your browser with the Web Audio API and an autocorrelation algorithm. Nothing is recorded and nothing is uploaded to a server.
What does the cents reading mean?
Cents measure how far you are from the target note, where 100 cents equals one semitone. Zero cents is perfectly in tune, a positive number means sharp and a negative number means flat. Try to stay within a few cents of centre.
Which instruments can I tune?
Any pitched instrument that produces a clear sustained tone: guitar, bass, violin, viola, cello, ukulele, mandolin, brass, woodwind and voice all work. The tuner is chromatic, so it recognises every note rather than a fixed set of strings.
The tuner says it cannot use my microphone. What now?
Grant microphone permission when the browser asks, make sure no other application is using the mic, and load the page over HTTPS. If access still fails, the page shows a fallback message and you can tune by ear using the tone generator and note frequency chart.
Tune a specific instrument
Every instrument below opens the same chromatic tuner with the correct standard tuning notes and frequencies shown alongside it.