Mandolin Tuner Online
Eight strings, four courses, one microphone — the tuner picks out which course you’re playing, tells you which way to turn, and marks each one green as it settles. Free, no app, nothing recorded.
Tap a peg to hear its note and start tuning — the browser will ask for mic access once. Sound is analyzed on your device, never uploaded.
How to Tune a Mandolin Online
Four courses, eight strings, one string at a time.
Allow the Microphone
Press Tune my mandolin and approve mic access. All the pitch analysis happens locally on your device.
Pick One String of a Pair
Rest a fingertip on its twin to keep it quiet, then pick the open string. The tuner names the course and shows how sharp or flat it sits.
Small Turns, Then the Twin
Nudge the peg as directed until the needle goes green, then mute the tuned string and bring its partner to the same spot. Four green courses and you're done.
Eight Strings Without the Headache
Course detection, worded directions, and a green check when each pair agrees.
Recognizes the Course You Pick
Sound a string and the tuner knows whether it's the G, D, A, or E course — no manual stepping through the four targets. Tap a peg to pin one down.
Made for Paired Strings
Mute one string of a pair with a fingertip and tune its twin solo — the tuner tracks a single clear string far better than two ringing at once, which is exactly how mandolins should be tuned anyway.
Direction, Not Guesswork
The readout states tune up or tune down in words. On a mandolin's tight, short strings that matters — you'll know to make the peg move tiny before you touch it.
Reference Tones per Course
Each peg plays its target pitch aloud — perfect for matching the second string of a pair to the first, or for tuning fully by ear and verifying after.
No Recording, Ever
The signal is analyzed on your device frame by frame and discarded on the spot. Nothing is captured, stored, or sent anywhere.
Any Device With a Mic
Tune at the jam, in the kitchen, or backstage — phones, tablets, and laptops on iOS, Android, Chrome, Firefox, Safari, and Edge.
Your Mic Stays Private
Every frame of microphone audio is analyzed in your browser and immediately thrown away. Nothing is recorded, nothing is uploaded, and pressing Stop cuts mic access on the spot.
No Recording
Frames are analyzed and discarded
No Upload
The analysis runs in your browser
You're in Control
Stop ends mic access instantly
When the Chop Has to Ring True
Doubled strings double the ways to drift — and the reasons to check.
Bluegrass Jams
Eight strings agreed on pitch before the first kickoff
Pair Matching
Get each course's two strings dead even — the difference you can hear instantly
Before Recording
A slightly sour course is glaring on tape; two minutes here prevents it
New Players
Worded up/down hints take the mystery out of eight tiny pegs
Ear Training
Match a pair by ear, then let the needle judge how close you got
Fiddle Doubles
Same G-D-A-E as a violin — swap instruments without changing tuners
G-D-A-E, Twice Over
A mandolin carries the violin’s tuning — G3 D4 A4 E5 in perfect fifths, against A4 at 440 Hz — but doubles every note. Its eight strings are grouped into four unison pairs called courses, and the two strings of each course are meant to sound as one voice. That doubling is where the instrument’s shimmer and volume come from, and it’s also why mandolin tuning has one extra discipline that guitars and fiddles never deal with: the pair itself has to agree, not just the course with the target note.
Tune one string of each pair at a time
The core technique: silence one string of the course with a light fingertip, pick its partner alone, and tune that single string to the needle. Then swap — mute the freshly tuned string and bring the second one up to match, either against the needle or by ear against the first. When both strings ring together with no slow wah-wah beating between them, the course is set. Trying to tune with both strings sounding gives the tuner two near-identical pitches at once, and the reading swims.
Why a slightly-off pair sounds so sour
Two strings a few cents apart don’t sound like two notes — they sound like one queasy note, pulsing at the rate of their frequency difference. That accidental chorus effect is the signature sound of an untended mandolin, and it can persist even when each string individually looks “close enough” on a dial. It’s also why the ±5 cent green zone matters more here than on single-strung instruments: the tighter each string lands, the tighter every pair agrees.
High tension, tiny turns
Mandolin strings are short, stiff, and strung at high tension, so a peg movement that would barely register on a guitar sends a mandolin string sailing past its target. Make the smallest adjustments you can manage, re-pick between each one, and come up to the note from below — strings pulled up to pitch stay put better than strings let down onto it. If a string is far off and the auto-detect briefly guesses the wrong course, tap the correct peg to lock the target and carry on.
More tuners on the shelf
The same engine covers the rest of the string band: guitar, violin (the mandolin’s single-strung twin), banjo, ukulele, and cello, each with its own targets and reference tones. Curious what note anything is? The note identifier names whatever it hears — and the online audio editor is waiting once the pairs ring clean.
Pairs Ringing Clean? Record Them
The full Notevibes Online Audio Editor records your playing, cleans up room noise, detects key and tempo, and exports to MP3 or WAV — all in your browser.
Free to try · No credit card required
Related Audio Tools
More free AI audio tools from Notevibes — same engine, no sign-up.
Violin Tuner
Tune G D A E with your mic — bow or pluck.
Guitar Tuner
Tune all six strings with your mic — auto string detection.
Banjo Tuner
Tune a 5-string banjo to open G with your mic.
Ukulele Tuner
Tune G C E A with your mic, string by string.
Pitch Detector
Read the live pitch of any sound — Hz, note, and cents.
Note Identifier
Sing or play a note and see its name instantly.
Mandolin Tuner FAQ
How do I tune a mandolin with this online tuner?
Press the button, allow microphone access, and pick one string at a time. The tuner identifies the course, shows the offset in cents, and says tune up or tune down. Turn the peg in small moves until the needle centers and goes green, hold briefly for the check mark, then do the same for the other seven strings, pair by pair.
What tuning does a mandolin use?
G3 D4 A4 E5 in perfect fifths — the same notes as a violin, referenced to A4 = 440 Hz. The difference is that a mandolin doubles each note: eight strings arranged in four unison pairs, called courses, so every note you fret sounds twice.
Should I tune both strings of a pair at once?
No — one at a time. Lightly rest a fingertip on one string of the course to silence it, tune its partner until it lands, then swap and match the second string to the first. Two strings ringing together beat against each other, which makes any tuner's reading wobble.
Why does my mandolin sound sour even when the tuner says it's in tune?
Almost always the pairs. Each string can be individually close to pitch while the two strings of a course sit a few cents apart from each other — that mismatch produces the mandolin's characteristic detuned chorus shimmer. Re-check each course string against string, not just against the target note.
Why do tiny peg turns change the pitch so much?
Mandolin strings are short and under high tension, so a small rotation makes a big pitch move. Turn in the smallest increments you can, re-picking between adjustments, and approach the target from below — nudging up to pitch holds better than drifting down onto it.
Is anything recorded or uploaded?
No. Audio is analyzed live on your own device and thrown away frame by frame — nothing is stored or transmitted, and the microphone releases the moment you press Stop.
Is it free?
Completely free, no strings attached — no sign-up, no install, no limits. It runs in your browser and needs only microphone permission, revocable anytime.