FFT Analyzer
Paste a time-domain signal (comma/newline separated samples) and a sample rate. Returns the magnitude spectrum, top 5 peak frequencies, and a visual plot.
Up to 8,192 samples. Non-power-of-2 lengths are zero-padded.
Cooley-Tukey radix-2 FFT. Inputs are zero-padded to the next power of 2. Output magnitudes are normalized by N and doubled for non-DC/non-Nyquist bins to reflect the conjugate-symmetric spectrum of a real signal.
Limitations: Magnitude only (phase discarded). No windowing (rectangular) — long signals with non-integer-cycle content will show spectral leakage. Max 8,192 samples.
What to do next: To check a tone of 50 Hz, sample at ≥100 Hz (Nyquist). 1 second of 1000-Hz samples gives 1-Hz frequency resolution. For longer signals, chunk them and average magnitude spectra.