Open the Online Tuner
Free online instrument tuner. Use your microphone to tune guitar, bass, ukulele, violin or cello, or any note with the chromatic tuner.
- Free to use
- No signup
- Nothing to install
- Runs in your browser
Guitar A string reads 108.9 Hz (A2 −17 cents flat) → tighten slightly until it reads 110.0 Hz and turns green.Open the Online Tuner
Illustration. Open the tool for the real thing.
What is the Online Tuner?
This online tuner listens to your instrument through your microphone and shows the note you are playing, its frequency in hertz and — most importantly — how many cents sharp or flat it is. A needle swings to the centre and turns green when the string is within five cents of perfect pitch, so you can tune by eye without any special hardware.
Choose a chromatic tuner for any note, or presets for standard guitar (E A D G B E), bass, ukulele, violin and cello. Tap a string button to hear a reference tone and see the target frequency, and change the A4 reference from 415 to 466 Hz for baroque, orchestral or alternative tunings. Pitch is measured in your browser with a normalised autocorrelation algorithm, and no audio ever leaves your device.
3 steps to your result
Open the tool and follow along. Nothing to install.
What you get
See exactly how sharp or flat each string is.
Guitar, bass, ukulele, violin, cello and chromatic.
Tap a string to hear the target pitch.
Tune from 415 to 466 Hz for any repertoire.
AZRS tools are free to open and use.
It opens in your browser, so there is nothing to download.
Used for
Pick one to see how it fits.
How it compares
A plain look at this tool next to the usual alternative.
| This utility | Desktop software | |
|---|---|---|
| Install | Nothing to install | Usually an app or program to install |
| Account | No signup | Depends on the product |
| Cost | Free to use | Free or paid, depends on the product |
| Where it runs | In your browser tab | On your computer |
Questions people ask
How does the tuner work?
It records short sound windows from your microphone and finds the repeating period of the waveform (autocorrelation), then converts that frequency to the nearest note and the offset in cents.
What are cents?
There are 100 cents in a semitone. Within about ±5 cents most people cannot hear that a note is out of tune.
What is A4 = 440 Hz?
The standard concert pitch. Some ensembles use 442 or 432 Hz, and baroque music often uses 415 Hz.
Why does it not detect my note?
Play louder or closer to the microphone, reduce background noise, and play one note at a time.
Does it work for bass and low notes?
Yes, down to about 30 Hz (low B on a five-string bass).
More free tools
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Try the Online Tuner now
Tune any instrument with your microphone — live pitch, note and cents. Free to use.
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