FIR Filter Designer (Web)

How to use — FIR Filter Designer

1. Wait for Python runtime to finish loading (first load may take a bit).
2. Set parameters at the top:
   • Sampling Frequency (Hz) = your signal’s sample rate.
   • Filter Length (taps) = sharpness vs. speed trade-off.
   • Low/High Frequency cutoffs (must be < Nyquist, i.e., fs/2).
   • Filter Type: Lowpass / Highpass / Bandpass / Bandstop.
   • Window (tooltip explains behavior) + Response Type.
   • Optional: Show Phase Response.
3. Click Design Filter to render plots.

Plots: impulse/step, window (time), filter magnitude (±phase), window magnitude, plus a demo “raw vs filtered” signal.

Export: use Export Coefficients (CSV) and Export Plots (PNG). A metadata TXT is included.

Troubleshooting:

• “Cutoffs must be < Nyquist” → lower the cutoffs or raise fs.
• Bandpass/Bandstop require lowcut < highcut.
• First load is heavy; give it a moment.