A free online tuner that listens through your device's microphone. Play one string at a time: the tuner works out the note, picks the string you are most likely tuning, and the needle shows how many cents (hundredths of a semitone) the string is flat or sharp. Within 3 cents the display turns green and the string gets a tick. The striped bar under the needle works like a strobe tuner: it drifts left when the note is flat and right when it is sharp, faster the further off it is, and stands still when the string is in tune.
It works for acoustic and electric guitar (hold the phone near the sound hole, or near an amplifier), bass, ukulele, violin, viola, cello, mandolin and banjo, and the chromatic mode names any note from any instrument or a voice. The pitch is found with the McLeod pitch method, which follows the fundamental of a string rather than its brighter overtones, and the reading is accurate to better than a cent on a clear note.
- How accurate is this online tuner?
- On a clear, steady note it measures the pitch to within a cent (a hundredth of a semitone), which is finer than the ear can hear and as fine as a good clip-on tuner. The display is smoothed over a few readings so it settles instead of flickering. The reading is only as good as the sound reaching the microphone, so play one string at a time, mute the others, and keep noise down.
- The needle jumps around or shows the wrong string. What can I do?
- Pluck firmly and let the string ring rather than strumming several. Hold the phone closer to the guitar (near the sound hole, or the amplifier for an electric). In a noisy room turn Sensitivity down; for a quiet instrument turn it up. If a string is far out (a whole tone or more), the tuner may think you are tuning the neighbouring string: tap the string you mean so it tunes to that one.
- What do flat and sharp mean?
- Flat means the note is lower than it should be, so the string needs tightening (tune up). Sharp means it is too high, so loosen it (tune down). It is easiest to tune up to the note: if you overshoot, go below it and come back up, which keeps the string from slipping.
- Which tunings can it do?
- For guitar: standard E A D G B E, drop D, half step down (E♭ A♭ D♭ G♭ B♭ E♭), whole step down, drop C, DADGAD, open G, open D, open E, open C and 7-string standard. There are also bass, ukulele, violin, viola, cello, mandolin and banjo tunings. For anything else, choose Chromatic: it names the nearest note to whatever you play.
- Should I tune to 440 Hz or 432 Hz?
- 440 Hz for A4 is the standard almost everywhere, and what other instruments and recordings will match. Some orchestras tune a little higher (442 or 443), and some players like 432 Hz. Set the reference to match the people or the recording you play with; every string's target moves with it.
- Is the microphone recording me?
- No. The sound is measured in your browser a few dozen times a second to find the pitch and is then discarded. Nothing is recorded, uploaded or stored. The microphone is turned off when you press Stop tuner, switch to another tab or app, or leave the page.
- Can I tune with my iPhone or Android phone?
- Yes, in Safari, Chrome, Firefox or Edge. Allow the microphone when asked. If you said no earlier, allow it again in the site settings (on an iPhone, the "aA" menu in Safari's address bar, Website Settings) and reload. If the reference notes are silent on an iPhone, check the silent switch and the media volume.
- Can I tune by ear instead?
- Yes. Tap a string to hear its note, made by the page at the exact pitch for the reference you set, and tune until the string and the note sound the same, with no slow wobble ("beating") between them. This works without a microphone.