Ukulele Tuner

How to tune your ukulele online

1. Choose your tuning.

   Pick Re-entrant (standard gCEA), Low G, or Baritone, matching your ukulele type.

2. Click "Start Tuning."

   Allow microphone access when your browser asks.

3. Pluck a string.

   The closest peg on the headstock highlights automatically, or tap a peg to target that string directly.

4. Watch the meter.

   Turn the tuning peg slowly — left means flat (tighten), right means sharp (loosen).

5. Repeat for all 4 strings.

   Then double-check all four again, since tuning one string can slightly pull the others.

How this tuner detects pitch

When you pluck a string, this tool analyzes the sound through your microphone using an autocorrelation algorithm — it compares the waveform against slightly delayed copies of itself to find the point where they line up most closely, and that lag reveals the exact frequency you're playing. This runs entirely in your browser via the Web Audio API; your microphone audio is never recorded, uploaded, or sent anywhere, and it disappears the instant you close the tab.

Troubleshooting a jumpy or inaccurate reading

The needle won't settle, or jumps between notes

Background noise is the most common cause — a fan, a TV, or other instruments ringing nearby all confuse pitch detection. Mute any strings you're not testing and play a single, clean note rather than a chord.

It picks the wrong string

In Auto mode, a string that's very badly out of tune can land closer to a neighboring string's target pitch than its own, so the tuner locks onto the wrong one. Switch to manual string selection until it's roughly in range, then Auto mode will track it correctly from there.

Nothing registers at all

Check that microphone permission was actually granted — look for a blocked-mic icon in your browser's address bar — and confirm you're playing firmly enough for the microphone to pick up a clear signal above any background noise.

Ukulele types and their standard tuning

Soprano is the smallest and most common size, with the classic bright, chiming ukulele tone. Concert is a little larger with slightly more volume and easier fret spacing. Tenor is bigger still, favored by many performing players for its fuller sound, and can come with either tuning depending on the strings installed. Baritone is the largest and lowest-pitched, tuned identically to a guitar's top four strings, which is exactly why it's such a comfortable transition for guitarists.

Re-entrant vs. Low G — what's the real difference?

Re-entrant tuning (G4-C4-E4-A4) is what most people think of as "the" ukulele sound. The trick is in that G string: rather than being the lowest-pitched string like you'd expect from its position, it's deliberately tuned an octave higher, sitting between the E and A strings in actual pitch. That's what "re-entrant" means — the pitch order re-enters a range it already covered. This unusual arrangement is exactly what gives strummed chords that bright, jangly, unmistakably ukulele character.

Low G tuning (G3-C4-E4-A4) swaps that high G for a thicker string tuned a full octave lower, so the strings now run in a normal, ascending low-to-high order like a guitar. This gives a noticeably deeper, more melodic range with an extra low note available, at the cost of that signature re-entrant sparkle. Some players keep two ukuleles strung differently just to have both options on hand.

Baritone tuning and playing guitar-style

A baritone ukulele's D-G-B-E tuning is identical to the four thinnest strings on a standard guitar, which is exactly why so many guitarists gravitate toward baritone ukes — every chord shape they already know from the top four guitar strings carries over directly, no relearning required. This tuning is sometimes called Chicago tuning. Combined with the baritone's larger body and longer scale length, it produces a notably deeper, more resonant sound than the other ukulele sizes.

Tuning by ear, string to string

Once one string is confidently in tune — the A string is the usual reference point — you can check the rest by ear using fretted notes that should match a neighboring open string:

• Press the E string at the 5th fret — it should match the open A string.
• Press the C string at the 4th fret — it should match the open E string.
• Press the G string at the 2nd fret — it should match the open A string.

This is a genuinely useful ear-training exercise even if you tune with this tool every time, since it builds the same pitch-matching skill musicians rely on constantly when playing with others.

Keeping your ukulele in tune longer

• Stretch new strings. After tuning, gently pull each string away from the fretboard a few times and let it snap back, then retune. Repeat a few times — this settles the string in much faster than playing alone would.
• Store it somewhere stable. Swings in temperature and humidity are one of the most common reasons a ukulele won't hold its tuning between sessions.
• Consider your strings and pegs. Older strings and cheaper friction pegs both tend to slip more; a fresh set of quality strings or upgraded tuners can make a genuine difference if your uke never seems to stay put.

More tools on ProDeviceTest

Practicing music rather than just tuning up? These run the same way — instant, no download, right in your browser.

• Guitalele Tuner — the guitar-ukulele hybrid, A or E tuning
• Guitar Tuner — standard 6-string tuning with an interactive headstock
• Banjo Tuner — 5-string Open G, Double C, and Sawmill tuning
• Chromatic Tuner — tune any instrument to any of the 12 notes
• Metronome — practice with a steady, accurate beat
• Pitch Detector — see the note, Hz, and cents deviation of any sound
• All Instrument Tuners — the full category