Hurtz - Tone Generator

Hurtz is a clean, precise audio tone generator. Dial in any frequency from 20 Hz to 20 kHz and hear it instantly — great for testing speakers and headphones, tuning instruments, or producing a steady reference tone.

FEATURES
• Any frequency, 20 Hz – 20,000 Hz, set by a slider or typed in exactly (with a log or linear scale).
• Four waveforms: sine, square, saw and triangle.
• Quick presets (100, 220, 440, 1k, 10k Hz).
• Nearest musical note read-out with cents (A4 = 440), handy as a tuning reference.
• Frequency sweep: glide smoothly from one frequency to another over a set time.
• Stereo mode: set a different frequency on the left and right channels, with a live difference (Δ) read-out. Useful for stereo and channel checks, and for binaural tones (use headphones).
• A live oscilloscope view of the waveform.
• Adjustable volume, and a large play/stop control.
• Works on iPhone and iPad.

Everything runs on your device. The app has no ads, no accounts, no tracking, and no internet access — it collects no data at all.

SAFETY
Sustained high-volume tones — especially very high or very low frequencies — can be uncomfortable and may risk hearing or small speakers. Start at a low volume.