Guitar & Tuning

Free Online Guitar Tuner — Tune Your Guitar in a Browser

A microphone-based chromatic tuner that works in any browser. No app, no download, no account. Here's how to use it and a complete reference for the most common guitar tunings.

By Alon Peretz · May 2026 · 5 min read

A guitar that's even slightly out of tune is immediately noticeable to everyone in the room, even people who can't explain why it sounds wrong. Tuning accurately before every session is one of the simplest habits a guitarist can build — and these days it doesn't require carrying any extra gear.

A browser-based chromatic tuner uses your phone or laptop's microphone and the Web Audio API to detect pitch in real time. Grant mic access once, pluck a string, and the tuner shows you the nearest note and how many cents flat or sharp you are.

Open the free chromatic tuner Works on phone or laptop. Grant mic access, pluck a string, tune up. No download needed.
Open the tuner →

How to tune a guitar in standard tuning

Standard tuning for a 6-string guitar from low (thickest string) to high (thinnest) is: E A D G B E.

A common mnemonic is Eddie Ate Dynamite Good Bye Eddie. The precise pitches are E2, A2, D3, G3, B3, E4 — spanning two octaves from the lowest string to the highest.

To tune using the browser tuner:

  1. Open musokit.com/tuner on your phone or laptop
  2. Tap "Allow" when the browser requests microphone access
  3. Pluck your lowest string (E2) and watch the needle
  4. Turn the tuning peg until the needle centres and the note reads "E"
  5. Repeat for each string: A, D, G, B, E

Always tune up to the correct pitch rather than down to it. If you overshoot and go sharp, back off below the note and approach from below — this keeps tension even across the string and helps the note hold its pitch longer.

Common guitar tunings

Standard is just the start. Here are the most widely used alternate tunings, what genre they're associated with, and the string notes from low to high:

Standard
E · A · D · G · B · E
Drop D
D · A · D · G · B · E
Open G
D · G · D · G · B · D
Open D
D · A · D · F♯ · A · D
DADGAD
D · A · D · G · A · D
Open E
E · B · E · G♯ · B · E
Half Step Down
E♭ · A♭ · D♭ · G♭ · B♭ · E♭
Full Step Down
D · G · C · F · A · D

A chromatic tuner works for all of these. It simply reads the pitch of whatever note you're playing and tells you what it is — you match it to the target note for your chosen tuning.

Tips for accurate tuning

Tune in a quiet environment

Microphone-based tuners pick up all sound in the room. Background music or conversation creates competing pitches that can confuse the pitch detection. Move to a quieter spot or use headphones with the tuner.

Let the note ring cleanly

Pluck the string firmly and let it ring out. A weak, muted pluck gives the tuner less signal to work with, making the reading less stable. The note will drift in pitch as it decays — tune based on the initial steady reading.

Check intonation at the 12th fret

Tuning open strings is only the first step. If your guitar's intonation is set correctly, the 12th fret harmonic and the fretted 12th fret note should both read exactly in tune. If the fretted note is sharp, the saddle needs to move back; if flat, it needs to move forward.

New strings go flat quickly

Freshly strung guitars detune rapidly for the first few hours as the strings stretch and settle. Tune, play for a few minutes, tune again. Repeat three or four times and the strings will stabilise.

Frequently asked questions

What are the standard tuning notes for guitar?

From low to high: E2, A2, D3, G3, B3, E4. Remembered as Eddie Ate Dynamite Good Bye Eddie.

Can I tune my guitar online without an app?

Yes. A browser-based chromatic tuner uses your device's microphone to detect pitch in real time. No download or account is needed — just grant microphone access when prompted.

Is Drop D tuning hard to learn?

Drop D requires just one string change from standard: lowering the low E string to D. The benefit is that power chords on the bottom three strings become a simple bar across the same fret, making riffs easier and heavier-sounding.

How accurate is a microphone-based tuner?

A well-implemented browser tuner using the Web Audio API can detect pitch to within 1–2 cents in a quiet environment. A cent is 1/100th of a semitone — close enough that even trained ears cannot hear the difference.

Ready to tune up? The MusoKit chromatic tuner works for guitar, bass, ukulele, violin, and any other instrument. No app to download.
Open the free tuner →