FREE TOOL · ON YOUR DEVICE
Guitar tuner online for free
Play a string and the tuner tells you which note is sounding and how many cents it is off. It has modes for standard guitar and drop D, 4-string bass, ukulele, violin and a chromatic mode for any instrument. The sound is analysed in your browser: nothing is recorded or sent.
- Free with an account
- Six tuning modes
- A4 from 432 to 446 Hz
- Press “Start tuning”
- Play a string
- Tune to the centre
HOW TO USE IT
Three steps.
Press “Start tuning”
Allow the microphone when the browser asks and choose your instrument.
Play a string
Let it ring. The needle shows whether it is sharp or flat and the text tells you to tighten or loosen.
Tune to the centre
When the needle sits in the centre and the note lights up, the string is in tune (±5 cents).
NEXT STEP
Keep going with these tools
Tuner: common questions
Why does it not detect the note?
Play one string at a time, close to the microphone and away from noise. Low bass strings need a good microphone; on a phone, hold it close to the instrument.
What is A440 and why can I change it?
It is the reference frequency of A4. Almost all music uses 440 Hz; some orchestras tune to 442 or 443 and some people prefer 432.
Is the sound recorded?
No. The microphone is only analysed in your browser while you tune, and it turns off when you press “Stop” or switch tabs.
Is my audio uploaded to a server?
No. The tool runs inside your browser: audio files are read and processed on your device and are not sent to Cocuyo or to any third party. The MP3 encoder is served from our own site. You can check it in your browser’s network tools: your file is not sent.
Is it really free?
Yes. You can try it before signing up; to keep using it, we ask for a free account, with no subscription. It uses no credits and does not count toward your 30 welcome uses: it has no usage cap.
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