Guitar tuner
Play a string, turn the peg until the needle is centred.
–
–cents
Strings
Tap a string to hear its note and tune to it; tap again to go back to automatic
Nothing leaves your device
This tool runs entirely in your browser. What you type, play or record here stays on your device: nothing is uploaded or saved on a server.
Example
Example: tuning a guitar to standard E A D G B E
Standard tuning, reference A4 = 440 Hz. Play each string open: the tuner picks the nearest string and shows how many cents (hundredths of a semitone) it is off.
- Cents are 1200 × log₂(played ÷ target): 108 Hz against 110 Hz is −32 cents, about a third of a semitone flat.
- “In tune” lights within ±3 cents held for 0.6 seconds; once it is lit, a wobble to ±5 cents keeps it.
- For the sharp B and E, loosen below the note and tighten back up to it.
| String | Note | Target | Played | Needle |
|---|---|---|---|---|
| 6th (thickest) | E2 | 82.41 Hz | 80.0 Hz | −51: Too low — tighten |
| 5th | A2 | 110.00 Hz | 108.0 Hz | −32: Too low — tighten |
| 4th | D3 | 146.83 Hz | 146.0 Hz | −10: Too low — tighten |
| 3rd | G3 | 196.00 Hz | 196.2 Hz | +2: In tune |
| 2nd | B3 | 246.94 Hz | 248.0 Hz | +7: Too high — loosen |
| 1st | E4 | 329.63 Hz | 331.0 Hz | +7: Too high — loosen |
Five strings to bring in, the G already right. Drop D changes only the 6th string, to D2 at 73.42 Hz.
How it works
- Press Start tuner and allow the microphone when the browser asks.
- Play one string at a time: the tuner finds the nearest string and shows whether it is too low or too high.
- Turn the peg until the needle is in the middle and “In tune” lights up; tap a string to hear its note.
Frequently asked questions
- What are the notes of the guitar strings?
- In standard tuning, from the thickest string: E2, A2, D3, G3, B3, E4 — “Eddie Ate Dynamite, Good Bye Eddie”. Drop D lowers the sixth string to D2.
- How accurate is it?
- Within a cent or two: the pitch is measured by autocorrelation (the YIN method) over several periods of the note, and the needle shows cents — hundredths of a semitone. “In tune” lights up within ±3 cents.
- Why does the tuner not hear anything?
- The browser needs permission to use the microphone — press Start and allow it, or check the icon next to the address bar. Play one string at a time, close to the phone or laptop, in a quiet room.
- Should I tune up or down to a note?
- Up: if a string is sharp, loosen it below the note and bring it back up. The string then holds its pitch better.
- What frequency is each guitar string?
- At A4 = 440 Hz: E2 82.41 Hz, A2 110 Hz, D3 146.83 Hz, G3 196 Hz, B3 246.94 Hz and E4 329.63 Hz. Half step down lowers all six by a semitone, so the low string is E♭2 at 77.78 Hz.
- What do the cents mean?
- A cent is a hundredth of a semitone. −32 means the string is about a third of a semitone low; ±3 or closer counts as in tune once it holds for 0.6 seconds.
- Is my playing recorded?
- No. The sound is analysed in your browser as it comes in and is never recorded or uploaded.
Made for a specific use
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