Frequency Generator: Hz Tone

Frequency Generator turns your phone into a clean, precise tone generator. Pick any frequency from 1 Hz to 22 kHz, see the musical note it matches, and play it through your speaker or headphones.

A BIG, CLEAR DIAL
• The frequency sits in large digits you can read at a glance, with the nearest note (A4 = 440 Hz)
• Drag the logarithmic slider, tap − and + for single steps, or tap the number to type an exact value
• Step size 1 Hz or 0.1 Hz; hold − or + to move ten steps at a time
• Quick presets: 20 Hz, 50 Hz, 100 Hz, 440 Hz, 1 kHz, 10 kHz and 17.4 kHz
• Your last frequency, volume and waveform are remembered for next time

FREQUENCY SWEEP
• Glide from 20 Hz to 20 kHz to find rattles, resonances and dead spots in a speaker, subwoofer or room
• The full sweep runs logarithmically in 20 seconds, so every octave gets the same time
• The display follows the sweep live so you know exactly where the rattle happens

HEARING RANGE TEST
• With headphones, a tone rises from 8 kHz; tap the moment you can no longer hear it and see your upper limit
• Most young adults hear up to about 15–17 kHz, and the limit drops with age
• This is a fun check, not a medical hearing test

OUTPUT CONTROL
• Volume slider that starts low, and a Left / Both / Right switch to check each channel and your stereo wiring
• A short safety reminder appears before the first tone plays

PREMIUM TOOLS
• All 6 waveforms: square, triangle, sawtooth, white noise and pink noise on top of sine
• 0.01 Hz precision for tuning instruments, lab work and resonance hunting
• Custom sweep: your own start, end, duration (1 second to 10 minutes), linear or logarithmic, and loop
• Dual tone: a different frequency in each ear to hear beat frequencies, with the right ear offset up to ±50 Hz in 0.5 Hz steps
• Auto-stop timer (1, 5, 10 or 30 minutes) and export of a 10-second WAV file to share or use elsewhere
• Exported WAV files are 44.1 kHz with a soft fade in and out, so they start and end without a click

WHAT PEOPLE USE IT FOR
• Speaker and subwoofer checks: find buzzing panels, loose parts and the frequency where a room booms
• Headphone and stereo checks: confirm left and right are not swapped and both drivers work
• Music: play a reference pitch such as A4 = 440 Hz to tune by ear
• Classroom and hobby experiments: sound waves, beats, resonance and the limits of human hearing
• Audio projects: create a test tone file for a mixer, amplifier or recording setup

HOW TO USE
1. Turn the volume down first
2. Choose a frequency with the slider, a preset or by typing it
3. Tap Play tone, then raise the volume slowly until it is comfortable
4. Use the sweep or hearing test from the same screen whenever you need them
5. Tap Stop when you are done, or set the auto-stop timer with Premium

GOOD TO KNOW
• The tone stops when you leave the app, so nothing keeps sounding in your pocket
• Most phone speakers play little below about 100 Hz; for deep bass tones use headphones or an external speaker
• Very high tones may be silent on some headphones even when your ears could hear them

FREE TO START
• Tone generator, sweep, hearing test and presets are free, with no ads
• Premium is available as a monthly or yearly subscription or a one-time lifetime purchase. Payments are processed by Google Play Billing, and subscriptions can be cancelled any time in Google Play

SAFETY
Start at a low volume and raise it slowly. Very low or very high tones can be louder than they sound, and long loud tones can damage hearing and small speakers. Tones are for testing, music and entertainment and are not a medical treatment.

PRIVACY
Tones are generated on your device. Nothing is recorded and the app needs no microphone, location or contacts permission. Firebase Analytics and Crashlytics help us see which features get used and fix crashes; you can switch that off in Settings.

No account. No sign-up. No ads.

Recent changes:
Stability and memory improvements, safer back navigation, smaller and cleaner builds.