Chords depend on every string agreeing
An open chord blends several strings at once. If even one is a little sharp or flat, the chord loses its clean ring and can sound subtly "off" even to listeners who don't play an instrument.
100% free · No sign-up · Audio never leaves your device
Guitar Tuner — Tune Every String, Every Tuning Right From Your Browser
A free online guitar tuner that listens through your microphone and tells you exactly how close each string is to pitch. Auto Detect finds the nearest string for you, switch between Standard, Drop D, Half Step Down, Open D, Open G and DADGAD in one tap, or play a reference tone for any string and tune entirely by ear.
- 6 stringsE2 · A2 · D3 · G3 · B3 · E4
- 6 tuningsStandard to DADGAD
- Reference tonesTune by ear too
- 0 uploadsFully on-device
Online Guitar Tuner
Auto Detect finds your string automatically, or pick one manually below.
Microphone: not connected yet
Tip: press Space to start or stop tuning at any time.
Tuning:
Target: E2 string · 82.41 Hz
🔊 Hear a string:
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0.0 Hz
Play an open string to begin
Current note
--
Target string
E2
Frequency
-- Hz
Target frequency
82.41 Hz
Cent deviation
--
Sharp / flat
--
Signal strength ?
Processing happens entirely inside this page. No audio is uploaded, recorded, or shared.
How to use the guitar tuner
Pick a tuning, then three simple steps.
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Step 1
Choose your tuning and allow the mic
Pick Standard, Drop D or another tuning above the dial, then press Start Tuning and allow the browser prompt. Nothing is recorded — each frame of audio is analyzed and discarded immediately.
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Step 2
Pick one open string
Leave Auto Detect on to let the tuner find the closest string, or tap a string name to lock it. Not sure what it should sound like? Tap its speaker button under Hear a String first.
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Step 3
Turn the tuning peg until it centers
Watch the needle, the cents number and the Sharp / Flat status. The dial turns green and shows In Tune when the string is centered.
Guitar tunings: Standard, Drop D and more
Every string, from lowest and thickest to highest and thinnest, at A4 = 440 Hz.
| Tuning | 6th | 5th | 4th | 3rd | 2nd | 1st |
|---|---|---|---|---|---|---|
| Standard | E2 · 82.41 Hz | A2 · 110.00 Hz | D3 · 146.83 Hz | G3 · 196.00 Hz | B3 · 246.94 Hz | E4 · 329.63 Hz |
| Drop D | D2 · 73.42 Hz | A2 · 110.00 Hz | D3 · 146.83 Hz | G3 · 196.00 Hz | B3 · 246.94 Hz | E4 · 329.63 Hz |
| Half Step Down | Eb2 · 77.78 Hz | Ab2 · 103.83 Hz | Db3 · 138.59 Hz | Gb3 · 185.00 Hz | Bb3 · 233.08 Hz | Eb4 · 311.13 Hz |
| Open D | D2 · 73.42 Hz | A2 · 110.00 Hz | D3 · 146.83 Hz | F#3 · 185.00 Hz | A3 · 220.00 Hz | D4 · 293.66 Hz |
| Open G | D2 · 73.42 Hz | G2 · 98.00 Hz | D3 · 146.83 Hz | G3 · 196.00 Hz | B3 · 246.94 Hz | D4 · 293.66 Hz |
| DADGAD | D2 · 73.42 Hz | A2 · 110.00 Hz | D3 · 146.83 Hz | G3 · 196.00 Hz | A3 · 220.00 Hz | D4 · 293.66 Hz |
Select a tuning above the dial and the string buttons and reference tones update automatically — no need to
remember frequencies. Drop D and Half Step Down are common for metal and rock; Open D, Open G and DADGAD are
popular for slide, folk and fingerstyle playing.
Why accurate guitar tuning matters
A few cents off is not always audible on one string, but it compounds fast.
Playing with others exposes small errors
A slightly out-of-tune guitar is easy to miss alone but stands out immediately next to a piano, another guitarist, or a backing track tuned to concert pitch.
Alternate tunings raise the stakes
Open and modal tunings like Open G or DADGAD rely on specific intervals between strings to sound right. A single mistuned string can throw off every chord shape built around that tuning.
It protects your ear training
Practicing daily on an out-of-tune instrument slowly shifts your sense of what "in tune" sounds like. A quick check before every session keeps your ear calibrated to true pitch.
Tips for accurate guitar tuning
Most inaccurate readings trace back to one of these.
- Pluck one string at a time. Strumming or letting neighboring strings ring confuses which pitch is being measured.
- Mute the other strings if needed. Rest your fretting hand lightly across the strings you aren't tuning to stop them ringing sympathetically.
- Use a full, even pluck. A muted or muffled pluck doesn't give the tuner enough steady signal to lock onto — especially on the low E string.
- Reduce background noise. Fans, amps and music in the room are the most common cause of a jumpy or wrong reading.
- Retune top to bottom after big changes. Loosening or tightening one string shifts neck tension slightly, which can nudge the others out — do a second pass after the first.
- Let new strings settle. Fresh strings stretch and drift for the first few days; stretch them gently by hand and expect to re-tune more often until they stabilize.
Sharp vs flat: what the readout means
Two words, two directions on the tuning peg.
Sharp (♯) — too high
A sharp reading means your string is vibrating faster than the target frequency, so the pitch sounds higher than it should. The cents number is positive, and the needle sits to the right of center. Loosen the tuning peg slightly to bring it down.
Flat (♭) — too low
A flat reading means your string is vibrating slower than the target frequency, so the pitch sounds lower than it should. The cents number is negative, and the needle sits to the left of center. Tighten the tuning peg slightly to bring it up.
Aim for within about ±5 cents, shown as the green "In Tune" zone on the dial. Strings settle slightly after
each adjustment, so give a note a second to stabilize before making another correction.
Frequently asked questions
What are the standard guitar string notes and frequencies?
Standard tuning, from the thickest and lowest string to the thinnest and highest, is E2 (82.41 Hz), A2 (110.00 Hz), D3 (146.83 Hz), G3 (196.00 Hz), B3 (246.94 Hz) and E4 (329.63 Hz), assuming a concert pitch of A4 = 440 Hz.
How do I use this online guitar tuner?
Press Start Tuning and allow microphone access, then pick one open string at a time. Auto Detect picks the closest string for you, or tap a string name in Manual mode to lock it. You can also tap a speaker button under Hear a String to play that note out loud and match it by ear.
Is this guitar tuner free and does it need an app?
Yes. It runs entirely in your browser using the Web Audio API, so there is nothing to install and no account to create. It works the same way on a laptop, phone or tablet, in Chrome, Edge, Firefox or Safari.
Which alternate tunings does this tuner support?
Besides Standard tuning, you can switch to Drop D, Half Step Down (Eb standard), Open D, Open G and DADGAD with one tap. The string buttons and reference tones update automatically to match whichever tuning you select.
Does the tuner listen through my microphone, and is that private?
Yes, it uses your device microphone to capture sound and analyze the pitch frame by frame in your browser. Audio is not recorded, saved or uploaded anywhere — each frame is processed and discarded immediately.
What does the cents number mean when tuning a guitar string?
A cent is one hundredth of a semitone. The readout shows how many cents above or below the target string frequency your note currently sits. A reading within about 5 cents is generally considered in tune to the ear.
Can I hear the target note instead of relying on the microphone?
Yes. The Hear a String row plays a clean reference tone for any string in the current tuning through your speakers or headphones, so you can tune entirely by ear, or use it to double-check what the microphone is reporting.
Does this work for electric guitar, acoustic guitar and bass?
Yes for electric and acoustic guitar — just play into the microphone, or plug an electric into an interface or amp with a mic nearby. For bass guitar or any other instrument and full chromatic detection, use the main Pitch Detector or the Chromatic Tuner, which are not locked to a fixed string set.
Why does my guitar go out of tune so quickly after restringing?
New strings stretch significantly during their first few days of play. Stretch each string gently by hand after installing it, tune it back up, and repeat a few times — this speeds up settling and reduces how often you need to re-tune.
What is a good reference pitch (A4) to use, 440 Hz or 442 Hz?
440 Hz is the standard concert pitch used by most recordings and method books, and is the default here. Some players tune slightly higher, around 442 Hz, for a brighter sound or to match another instrument. Use the reference pitch slider to match whoever you are playing with.
Related tools
Chromatic Tuner
The same detection engine, free to tune any note on any instrument — bass, piano, ukulele and more.
Violin Tuner
Auto and manual G-D-A-E string tuning built the same way as this guitar tuner.
Voice Pitch Analyzer
Track your voice's pitch, frequency and cent deviation live while you speak, hum or sing.
Need to tune a different instrument?
The main Pitch Detector uses the same engine, built for any sustained note on any instrument.