OpenTuner: String Tuner

OpenTuner is a string tuner that only tunes. Pluck a string and it tells you if the string is loose, too tight or in tune.

HOW TO READ IT • Left of the center line: the string is loose. Tighten it. • Right of the line: it is too tight. Loosen it. • On the line: in tune. A green ring closes around the marker, a chime plays, and the string gets a green check. The trail below the marker scrolls down and shows how you got there.

INSTRUMENTS • Ukulele: standard, low G, D tuning • Baritone ukulele • Cavaquinho: standard, natural • Guitar: standard, drop D, half step down, whole step down, DADGAD, open G, open D • 7-string guitar: low C, low B • Viola caipira: cebolão in E, cebolão in D, rio abaixo • 4, 5 and 6-string bass • Violin (beta)

Standard tuning is already picked. OpenTuner hears which string you played, or you can tap a string to lock it.

SIMPLE ON PURPOSE • No ads. Not now, not later. • No account, no tracking, no in-app purchases. • Only one permission: the microphone. Sound is analyzed on your phone and never recorded. • No internet permission, so it works anywhere, offline. • Light and dark themes, C D E or Do Re Mi note names, adjustable reference pitch (A4).

OPEN SOURCE OpenTuner is free and open source under the Apache 2.0 license. The code is on GitHub: github.com/guilhermefeitosa66/open-tuner