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Kepma Online Tuner · Professional Chromatic and Instrument Tuner with Spectrum Analysis
The Kepma online tuner runs entirely in your browser: open the page, allow microphone access and the needle settles within a second. Nothing is uploaded and no connection is required once the page has loaded. It is built for guitar work but equally at home with bass, ukulele, violin, erhu, guqin or any fretted or fretted-less instrument, because the reference database covers more than a hundred tunings across nine instrument families.
What it does beyond showing you a note
The detector uses the McLeod Pitch Method, which measures the time-domain signal rather than just picking the loudest FFT bin. That distinction matters: on many instruments the second harmonic is stronger than the fundamental, so a naive tuner reports the wrong note an octave up. A median filter suppresses octave jumps, and a 22 Hz high-pass plus a 2.2 kHz low-pass at the input reject rumble and hiss before anything is measured. Accuracy sits around ±0.1 cents.
Temperaments, transposition and the reference pitch
Seven historical temperaments are included, from equal temperament through just intonation, Pythagorean, quarter-comma meantone, Werckmeister III, Kirnberger III and Vallotti, each with a plain-language description of where it came from and what it costs you. Transposing instruments are handled by listing them in B-flat, E-flat, F, A, G and D. The reference pitch is adjustable from 380 to 520 Hz, with one-tap presets for the common historical values from 415 Hz Baroque through 440 Hz international standard to 445 Hz Viennese.
Cents, the spectrum view and octave stretch
The cents needle gives ±50 cents of resolution with a clearly marked ±5-cent in-tune zone, and the spectrum view shows the fundamental alongside its harmonics so you can see why a note reads where it does. The octave stretch control reproduces the Railsback curve that piano tuners use to align harmonics across octaves. Hold a string and the reference tone together to hear the beating slow down as you close in; when the beat disappears you are there.
Custom tunings and everyday use
Any tuning can be saved as a custom preset, named, edited and starred, and the whole set of settings plus your custom tunings can be exported to a file and re-imported on another device. Everything stays in local storage on your own machine. For field setup, running a luthier bench check or simply checking a new set of strings, it is the same three seconds every time.
How to use
Kepma Multi-Instrument Tuner
Kepma Multi-Instrument Tuner：Tunes a wide range of instruments and alternate tunings, with frequency calibration, background-noise reduction, tuning tolerance, and real-time frequency analysis.
tuner · Features and controls
- Built-in tuning for guitar, ukulele, bass, violin, cello, erhu, pipa, zhongruan, liuqin, and more.
- Includes alternate guitar tunings and adjustable A4 calibration, set to 440 Hz by default.
- Offers one-click background-noise reduction and adjustable tuning tolerance; notes within 8 cents are considered in tune by default.
- Displays a real-time frequency spectrum and basic FFT, useful for monitoring pitch stability during vocal practice.
Using the tool in a practice session
Start with one clear practice task and change one setting at a time. Check the selected tuning, scale or rhythm before comparing the display and the sound. Where playback is available, begin at a comfortable volume and listen to a short passage before adding notes or increasing speed. Return to your own guitar and repeat that passage to check whether you can reproduce the notes, timing or fretboard relationship. Keep a short record of the settings you chose and the part that still needs work. In your next session, review the same task before switching to a new one.
Choose a small musical goal before starting: keeping an even pulse, recognising a note, or understanding one shape. Work on that goal for a few minutes instead of changing several controls together. Check the selected instrument layout against your own instrument, especially after using an alternate tuning or switching handedness.
Compare what you hear with what you see. Say the note names or count the beats aloud, then repeat the exercise without relying on the screen. If an answer or performance is uncertain, slow down and check one element at a time. A visual result is most useful when you can explain it and reproduce it yourself.
For a fair comparison, keep the device, volume and settings consistent. Stop playback before changing to another exercise. Review the feature list above to choose the next task, and return to the directory when you need a different kind of practice tool.
