How does this online guitar tuner work?

Strum Lab uses the Web Audio API and high-speed pitch detection DSP (digital signal processing) directly inside your web browser. When you pluck a guitar string, your microphone captures the sound wave, and our algorithm measures the exact fundamental frequency in Hertz (Hz) to determine whether you are sharp, flat, or in tune.

What are the standard guitar string notes and frequencies?

Standard guitar tuning (from lowest pitch to highest) is: 6th String = E2 (82.41 Hz), 5th String = A2 (110.00 Hz), 4th String = D3 (146.83 Hz), 3rd String = G3 (196.00 Hz), 2nd String = B3 (246.94 Hz), 1st String = E4 (329.63 Hz).

Can I tune an electric guitar without plugging it in?

Yes! Unplugged electric guitars produce enough acoustic resonance for sensitive device microphones (especially smartphones and modern laptops) to detect cleanly in a quiet room. Hold your guitar body close to your microphone or connect an audio interface for zero-noise detection.

How do I tune to Drop D tuning?

To tune to Drop D, keep strings 1 through 5 in standard tuning (E B G D A), and tune only the 6th string down one whole tone from E2 (82.41 Hz) to D2 (73.42 Hz). Strum Lab has an instant Drop D preset mode that detects D2 automatically.

Is Strum Lab completely free?

Yes, 100% free! All 20+ instrument tunings, the metronome with tap tempo, the background noise cleaner, and the 2-band equalizer are completely free without any paywalls or subscriptions.

What is the difference between 440 Hz and 432 Hz?

A4 = 440 Hz is the modern ISO standard concert pitch adopted internationally. A4 = 432 Hz (often called Verdi pitch) is slightly lower, producing a warmer, mellow resonance favored by some acoustic and classical musicians. Strum Lab lets you calibrate A4 reference frequency freely in the settings.

Free Online Guitar Tuner with Real-Time Microphone Detection

Tune acoustic, electric, classical guitar, bass, and ukulele instantly in your browser with zero latency and high precision. No downloads, no apps, 100% free.

Standard Guitar Tuning Notes & Frequencies (E A D G B E)

String	Note	Octave	Frequency (Hz)	Wavelength
6th String (Thickest)	E	E2	82.41 Hz	416 cm
5th String	A	A2	110.00 Hz	312 cm
4th String	D	D3	146.83 Hz	234 cm
3rd String	G	G3	196.00 Hz	175 cm
2nd String	B	B3	246.94 Hz	139 cm
1st String (Thinnest)	E	E4	329.63 Hz	104 cm

Free Online Guitar Tuner with Real-Time Microphone Detection

Standard Guitar Tuning Notes & Frequencies (E A D G B E)

Drop D Guitar Tuner

Drop C Guitar Tuner

Bass Guitar Tuner (4 & 5 String)

Ukulele Tuner (G C E A)