Online Tool Store
Instrument Tuner
Tune your guitar, ukulele, or bass using your microphone, with real-time note detection, frequency reading, and a cents-accurate needle display. Runs entirely in your browser.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
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Press Start and play a note
How the instrument tuner works
- Choose your instrument and its standard tuning.
- Press Start and allow microphone access, then play one string or note at a time.
- The tuner shows the detected note, its frequency, and a needle showing how sharp or flat you are.
The method
Autocorrelation compares the microphone's waveform against a time-shifted copy of itself at many different offsets, looking for the offset where they match best - that offset is the period of the fundamental pitch. The detected frequency is then compared against the closest target note's frequency to compute a cents deviation.
FAQ
How does pitch detection work without special hardware?
The tool uses an autocorrelation algorithm on your microphone's raw audio waveform to find the repeating period of the sound, then converts that period into a frequency in Hz.
Why does the tuner sometimes show no reading?
Background noise, a very quiet signal, or a note far outside typical instrument range can prevent a confident pitch reading. Play a clear, sustained single note close to the microphone.
What does "cents" mean on the needle display?
A cent is 1/100th of a semitone. The needle shows how many cents sharp or flat your note is from the target pitch - within about 5 cents is considered in tune for most purposes.
Which instruments and tunings are supported?
Standard guitar (EADGBE), standard ukulele (GCEA), and standard 4-string bass (EADG) - covering the most common tunings for each instrument.
How we compare
| Feature | Online Tool Store | Clip-on tuner | Mobile tuner apps |
|---|---|---|---|
| No hardware or app needed | ✓ | ✗ | ✗ |
| Free, no ads | ✓ | ✓ | Often ad-supported |
| Multiple instrument tunings | ✓ | Varies | ✓ |
For a quick tune-up without a clip-on device or an app store, Instrument Tuner is ready as soon as the page loads.