What Is Guitar Tuner?

Guitar Tuner is a browser-based instrument tuner that uses your device's microphone to detect pitch in real time. It shows you exactly how sharp or flat each string is, with a visual gauge that makes tuning quick and intuitive.

Whether you play acoustic guitar, electric guitar, bass, or ukulele, this tuner supports multiple instruments and tuning modes — from standard EADGBE to drop D, open tunings, and more.

Who Is This For?

Beginners

Need a reliable, easy-to-read tuner to get started

Intermediate Players

Switch between alternate tunings with ease

Multi-Instrumentalists

Play guitar, bass, and ukulele with one tool

Quick Tuning

Tune quickly without installing any app

Your Data Stays Private

100% Privacy Guaranteed: All audio processing happens in your browser. No recordings, no uploads, no tracking.

No Recordings

Microphone audio is analyzed in real time and never stored

No Uploads

Nothing leaves your device — everything stays local

No Tracking

We don't collect any usage data or personal information

How to Use Guitar Tuner

Enable Your Microphone

Click the Enable Microphone button and allow browser access when prompted. The tuner needs microphone input to detect the pitch of your strings.

Select Your Instrument and Tuning

Choose your instrument (Guitar, Bass, or Ukulele) from the dropdown menu. Then select your desired tuning — standard tuning is selected by default.

Play a String

Pluck a single string on your instrument. The tuner will automatically detect the pitch and show:

The detected note name and octave (e.g., E2, A4)
The deviation in cents from the target pitch
A visual gauge showing how far off you are

Adjust Your String

Follow the visual feedback to tune your string:

Green (center)

Your string is in tune

Yellow (near center)

Almost there, fine-tune slightly

Red (edges)

Significantly off, adjust more

The status message tells you whether to tune up (if flat) or down (if sharp).

Move to the Next String

Once a string is in tune (within ±5 cents), it gets a green marker. Move on to the next string and repeat until all strings are tuned.

Using Reference Tones

Tune by Ear: If you prefer tuning by ear, click any of the Reference Tone buttons at the bottom to hear the correct pitch for each string. Click again to stop playback.

Features

Real-Time Pitch Detection

The tuner uses the YIN algorithm — a highly accurate pitch detection method — to analyze audio from your microphone in real time. It detects frequencies between 50 Hz and 1200 Hz, covering all standard guitar, bass, and ukulele strings.

Frequency Detection Range 50-1200 Hz

Visual Tuning Gauge

A semi-circular gauge provides instant visual feedback. The needle moves smoothly to show how many cents sharp or flat your string is. Color-coded segments make it easy to see at a glance: red for far off, yellow for close, and green for in tune.

Multiple Instruments

Guitar (6-string)

Standard
Drop D
Half Step Down
Open G
Open D
DADGAD

Bass (4-string)

Standard
Drop D

Ukulele (4-string)

Standard (GCEA)
Low G
Baritone (DGBE)

Auto-Detect Strings

When you play a string, the tuner automatically identifies which string you're tuning based on the detected frequency. Strings that have been successfully tuned are marked with a green border.

Reference Tones

Each string has a reference tone button that plays a pure sine wave at the correct frequency. This is useful for tuning by ear or verifying your tuning in noisy environments.

Adjustable A4 Reference

The standard concert pitch is A4 = 440 Hz, but some ensembles and recordings use different references. You can adjust the A4 frequency from 430 Hz to 450 Hz, and all string frequencies update automatically.

Professional Flexibility: Adjust concert pitch to match orchestras (442 Hz), historical tunings (432 Hz), or any custom reference between 430-450 Hz.

Frequently Asked Questions

Why isn't the tuner detecting my guitar?

Make sure your browser has microphone access enabled. Play strings one at a time, close to the microphone. Background noise can interfere with pitch detection — try tuning in a quieter environment.

Check browser microphone permissions
Pluck strings individually and clearly
Move closer to the microphone
Reduce background noise

What does "cents" mean?

A cent is a unit of pitch measurement. One semitone equals 100 cents. If the tuner shows +10 cents, your string is slightly sharp (10/100 of a semitone above the target pitch). The goal is to get as close to 0 cents as possible.

Quick Reference: ±5 cents or less is considered in tune. ±10 cents is noticeable. ±50 cents is half a semitone off.

How accurate is this tuner?

The tuner uses the YIN pitch detection algorithm, which provides accuracy within ±1-2 cents under good conditions. For best results, pluck strings clearly and minimize background noise.

Tuning Accuracy ±1-2 cents

Can I use this on my phone?

Yes, the tuner works on any device with a microphone and a modern web browser. Mobile browsers (Chrome, Safari, Firefox) all support the required Web Audio API.

iOS: Safari, Chrome
Android: Chrome, Firefox, Edge
Desktop: All modern browsers

Why does the tuner show the wrong note?

This usually happens when multiple strings ring at once, or when harmonics are stronger than the fundamental frequency. Try muting other strings and plucking closer to the bridge for a cleaner tone.

Pro Tip: Mute adjacent strings with your fretting hand and pluck near the bridge for the clearest fundamental tone.

What is A4 = 440 Hz?

A4 = 440 Hz is the international standard for concert pitch. It means the note A above middle C vibrates at 440 cycles per second. Some orchestras and historical performances use slightly different references (e.g., 442 Hz or 432 Hz).

440 Hz

Standard concert pitch (ISO 16)

442 Hz

Common in orchestras

432 Hz

Alternative/historical tuning

Can I tune a 12-string guitar or 7-string guitar?

The tuner currently supports standard 6-string guitar, 4-string bass, and 4-string ukulele. However, you can still use it for other instruments — simply match each string to its target note using the chromatic display.

Chromatic Mode: The tuner detects any note, so you can tune additional strings by matching them to their target pitches manually.