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.