Sound Frequency Analyzer

Turn your phone into a real-time audio spectrum analyzer. Sound Frequency Analyzer captures live sound through your microphone, runs a fast Fourier transform (FFT), and shows the full frequency spectrum right in front of you — Hz across the bottom, dB up the side.

The dominant frequency is displayed in big, easy-to-read numbers, with the nearest musical note shown next to it (for example, 440 Hz ≈ A4). Great as a quick tuning reference or for seeing exactly what a sound is made of.

KEY FEATURES
▸ Live frequency spectrum (Hz vs dB), updated in real time
▸ Dominant frequency shown in large digits
▸ Nearest musical note (A4, C#5, and more) in standard notation
▸ Peak hold to freeze the highest points
▸ Freeze / resume to study a moment in detail
▸ Frequency band guides and 50/60 Hz hum reference lines
▸ Clean, distraction-free interface

WHO IT'S FOR
▸ Audio engineers and mixing engineers checking the spectrum
▸ Music producers analyzing tones and harmonics
▸ Musicians looking for a fast tuning reference
▸ Anyone diagnosing noise or electrical hum — quickly find power hum at 50 Hz or 60 Hz
▸ Teachers and students exploring sound and acoustics
▸ Audio demos and experiments

PRIVATE BY DESIGN
Everything runs on your device. No audio is recorded or saved, and no internet connection is required.

IMPORTANT — ACCURACY NOTE
A phone microphone has a limited frequency response. Very low and very high frequencies are captured less accurately, and absolute dB levels are not calibrated. This app is a practical measurement and diagnostic tool for everyday use — it is not a substitute for professional laboratory equipment.

Free to use, supported by ads.

Recent changes:
• Minor stability improvements