The free online FIR filter design tool

TFilter is a web application that generates linear phase, optimal, equiripple finite impulse response digital filters. It uses a pure javascript implementation of the Parks-McClellan filter design algorithm.

Usage

1. Set the sampling frequency and the desired number of taps.
2. Specify the passbands (gain > 0) and stopbands (gain = 0). Make sure they don't overlap.
3. Click the DESIGN FILTER button.

An example configuration is set up for you. To try it, just click the DESIGN FILTER button.