JustATuner

Free plan LinuxMacWindows

What JustATuner is

JustATuner is a free, open-source desktop tuner for musicians that combines a stroboscopic chromatic tuner with a just-intonation drone. The tuner displays 12 wheels for pitch classes, each with seven rings; users can adjust reference pitch, instrument transposition, cents bias per wheel, and octave bias per ring. The drone offers root, root-plus-fifth, major-triad, and minor-triad voicings in a pure sine or harmonic-stack sound. A live meter reports the just-intonation interval and cents difference, marking LOCKED when the reading is within 5¢ of just intonation. A Lissajous display visualizes interference between the played note and drone, with controls for phosphor color, trace thickness, trail count, and resolution. The app detects pitch through a microphone; its maker recommends a quality microphone and strongly recommends headphones when the drone is on. It is available for Windows, Linux, and macOS on Apple Silicon M1, M2, M3, and M4 chips. Linux use requires PortAudio, and a downloaded binary may need executable permission. The maker says the unsigned app may prompt an operating-system warning.

Who it suits

JustATuner suits musicians who want a desktop tuner with configurable pitch settings and a just-intonation drone. It is available on Windows, Linux, and Apple Silicon Macs.

What it does well

Free and open-source desktop software
Offers 12 pitch-class wheels with seven rings each
Drone supports four voicings and two sound types
Live meter reports interval and cents difference
Available for Windows, Linux, and Apple Silicon macOS

What to know first

Linux use requires PortAudio
Linux binary may need executable permission
Unsigned app may trigger an operating-system warning
Maker recommends headphones when the drone is on

Limits

The software is free and open source. Linux use requires PortAudio, and the downloaded binary may need executable permission; the maker also says the app is unsigned, which may prompt an operating-system warning.

Plans

Plan	Billed and limits	Price
Free	Desktop tuner and just-intonation drone · open source	Free

As stohrermusic.com lists them, read 2 Oct 2026. The maker's own page has the final word.

Getting started

Open the JustATuner page on the Stohrer Music website.
Choose the download for Windows, Linux, or macOS on Apple Silicon.
On Linux, install PortAudio and set executable permission on the binary if needed.
Launch the app and allow microphone access for pitch detection.
Use headphones when practicing with the drone, as the maker recommends.

Verdict

JustATuner combines pitch detection, stroboscopic displays, and drone-based intonation practice in a free desktop app. Check the platform requirements and be prepared for an operating-system warning because the app is unsigned.

Questions

How much does JustATuner cost?

It is free, with a Free plan listed as free.

Is there a free trial?

No. JustATuner is offered as free software rather than a trial.

Which platforms does it support?

It is listed for Windows, Linux, and macOS on Apple Silicon M1, M2, M3, and M4 chips.

Is JustATuner open source?

Yes. Its source code is available on GitHub for inspection.

Does it support just-intonation practice?

Yes. Its drone offers four voicings, and a live meter reports interval and cents difference.

Who makes JustATuner?

The software page identifies Matt Stohrer as its maker.

Facts from JustATuner's own pages

Downloads and signing: Downloads are hosted on GitHub, and the maker says the app is not signed with a developer certificate, so the operating system may show a warning. · stohrermusic.com, 2 Oct 2026
Drone practice: The drone supports root, root-plus-fifth, major-triad, and minor-triad voicings, with a pure sine or harmonic-stack sound. · stohrermusic.com, 2 Oct 2026
Instrument support: Transposition options include Concert, B♭, E♭, and F, and pitch-detection presets cover saxophones, voice, brass, and strings. · stohrermusic.com, 2 Oct 2026
Interval analysis: A live meter reports the just-intonation interval and cents difference, and marks LOCKED within 5¢ of just intonation. · stohrermusic.com, 2 Oct 2026
Linux requirement: Linux use requires PortAudio, and the downloaded binary may need its executable permission set. · stohrermusic.com, 2 Oct 2026
Maker: The software page identifies Matt Stohrer as the maker; his About page says he moved to North Carolina in 2010 and lives between Durham and Hillsborough. · stohrermusic.com, 2 Oct 2026
Microphone and headphones: The app listens to a microphone for pitch detection; the maker recommends a quality microphone and strongly recommends headphones when the drone is on. · stohrermusic.com, 2 Oct 2026
Pitch settings: Users can configure reference pitch, instrument transposition, per-wheel cents bias, and per-ring octave bias. · stohrermusic.com, 2 Oct 2026
Product: JustATuner is a free, open-source desktop tuner for musicians with a stroboscopic tuner and a just-intonation drone. · stohrermusic.com, 2 Oct 2026
Source code: The source code is available on GitHub for inspection. · stohrermusic.com, 2 Oct 2026
Stroboscopic tuner: Its chromatic tuner has 12 wheels, one for each pitch class, with seven concentric rings per wheel. · stohrermusic.com, 2 Oct 2026
Support: The maker lists [email protected] for questions or feedback. · github.com, 2 Oct 2026
Supported systems: The maker lists Windows, macOS on Apple Silicon, and Linux; the macOS app is for M1, M2, M3, and M4 chips. · stohrermusic.com, 2 Oct 2026
Visualizer: The drone’s Lissajous display visualizes interference between the played note and drone, with configurable phosphor color, trace thickness, trail count, and resolution. · stohrermusic.com, 2 Oct 2026

Where JustATuner stands on Freedom251

Musical Tuner Apps#11 of 32