A fast, private online guitar tuner
Keeping your instrument in tune is the most important step before any practice session or performance. This free online guitar tuner uses your device's built-in microphone to detect the pitch of your strings in real time. It provides instant visual feedback, showing you exactly which note you are playing, its frequency in hertz (Hz), and how far off it is from perfect pitch.
Because this is a tuner with microphone support that runs entirely in your web browser, it is exceptionally fast and completely private. The pitch detection algorithm analyzes the audio stream locally on your device. No audio is ever recorded, uploaded, or transmitted over the internet.
To ensure the most accurate reading possible, the tool automatically disables your browser's default echo cancellation and noise suppression features when it connects to your microphone. While those features are great for voice calls, they tend to filter out the sustained, rich overtones of a musical instrument. If the tool cannot hear your instrument, you may need to check your hardware using the Mic Test.
Supported instruments and tuning modes
Whether you play a standard six-string or a four-string acoustic, the tool includes built-in presets to help you find the right pitch quickly. When you select an instrument, the tuner automatically snaps to the nearest standard string for that instrument.
- Guitar Tuner: Set to standard E-A-D-G-B-E tuning. When you pluck a string, the tuner identifies which of the six strings you are trying to tune and guides you to the exact pitch.
- Bass Tuner: Set to standard E-A-D-G tuning for four-string bass guitars. The pitch detection algorithm is optimized to pick up the low frequencies of bass strings accurately.
- Ukulele Tuner: Set to standard G-C-E-A tuning (re-entrant tuning), perfect for soprano, concert, and tenor ukuleles.
- Violin Tuner: Set to standard G-D-A-E tuning in perfect fifths.
- Chromatic Tuner: If you use alternate tunings (like Drop D, DADGAD, or Half-Step Down), select the Chromatic mode. Instead of locking to specific strings, a chromatic tuner detects any of the 12 notes in the musical scale, allowing you to tune to any pitch you desire.
How to read the tuner
When you pluck a string, the tuner displays a large letter representing the detected musical note (e.g., E, A, C#) along with its octave number. Below the note, you will see the exact frequency in Hz and the deviation measured in "cents."
A cent is a unit of pitch equal to 1/100th of a semitone. The visual scale ranges from -50 cents to +50 cents:
- Too Low (Flat): If the needle is to the left of the center and the text says "Too low," your string is flat. You need to tighten the tuning peg to raise the pitch.
- Too High (Sharp): If the needle is to the right of the center and the text says "Too high," your string is sharp. Loosen the tuning peg to lower the pitch. It is often best to loosen it below the target note and tune up to it, which helps keep the string stable.
- In Tune: When you are within ±5 cents of the target pitch, the needle centers and the display turns green. Your string is now perfectly in tune.
Advanced tuning features
A4 Calibration By default, modern musical instruments are tuned to a standard where the A note above middle C (A4) vibrates at exactly 440 Hz. However, some musicians prefer different reference pitches. For example, some classical orchestras tune to 442 Hz for a slightly brighter sound, while some players prefer the alternative 432 Hz tuning. The calibration input allows you to adjust the A4 reference frequency anywhere between 430 Hz and 450 Hz. The entire tuner will recalculate its pitches based on your new reference point.
Tuning by Ear While visual tuning is highly accurate, training your ear is a valuable skill for any musician. When you select a specific instrument (like Guitar or Bass), a row of buttons appears at the bottom of the screen corresponding to the open strings. Clicking one of these buttons plays a two-second reference tone at the exact target pitch using your browser's audio engine. You can use this to match the pitch by ear. If you need to generate a specific frequency not listed here, you can use the Tone Generator.
Once your instrument is perfectly in tune, you are ready to play. If you are practicing timing and rhythm next, try using the online Metronome to keep your tempo steady.