Guitar Tuner
Free online guitar tuner. Tune acoustic or electric guitar and bass with accurate pitch detection, E-A-D-G-B-E tuning and ±5 cents precision. 100% local.
How does this online guitar tuner work?
It listens through your microphone and uses autocorrelation pitch detection — the same well-known algorithm used in many tuner apps — to measure the exact frequency of the string you pluck and compare it with the target pitch.
What tuning does it support?
Standard guitar tuning E-A-D-G-B-E (E2 82.41 Hz to E4 329.63 Hz). It also works for bass: the first four strings E-A-D-G use the same note names, though very low frequencies need a good microphone.
What does the cents indicator mean?
One cent is 1/100 of a semitone. The needle shows how far your string is from the target within ±50 cents, and turns green when you are within ±5 cents — the accuracy threshold for most ears.
Should I tighten or loosen the string?
If the reading is too high (sharp), the string is under too much tension — loosen it slowly. If it is too low (flat), tighten it a little at a time and pluck again.
Is my audio uploaded anywhere?
No. The sound is analysed locally in your browser in real time. Nothing is recorded, stored or sent to any server.
Why does detection fail or jump around?
Background noise, other instruments or a weak signal confuse pitch detection. Pluck one string at a time, play clearly, and tune in a quiet room with the mic close to the instrument.
Can I tune a ukulele or 7-string guitar?
The auto mode targets the six standard guitar strings. For other instruments, watch the detected note and frequency and tune until the needle centers on your desired pitch.
Do I need an electric tuner plug or interface?
No. Any built-in or external microphone works. For noisy stages, an clip-on vibration tuner is more reliable, but for home practice this browser tuner is fully sufficient.
How to Use Guitar Tuner
This guitar tuner analyses your instrument's sound entirely in your browser using autocorrelation pitch detection — the accurate algorithm behind professional tuner apps. Your audio never leaves the device and nothing is uploaded.
- Click "Start tuning" and allow microphone access when the browser asks.
- Pick a string button (E2–E4) or keep "Auto-detect string" enabled and let the tuner find the string for you.
- Pluck the string clearly and let it ring; the detected note and frequency appear under the big letter.
- Watch the needle: loosen the string when it shows "Too high", tighten it when "Too low", until the needle turns green within ±5 cents.
- Repeat for all six strings, then strum a chord to hear how well the guitar is in tune.
Tune upward to the pitch (loosen first if sharp, then tighten up to the note) — strings hold tuning better when the final adjustment tightens the gear.
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