FFT Toy 1.0, FFT Filters Made Simple, A Fast Fourier Transformation filtering tool for practitioners and students. FFTToy was developed to enable practitioners to quickly examine and filter signals. In addition, with FFTToy you can simply generate artificial vectors comprised of sine waves and then use those vectors to test your FFT filter. The tool computes a multiplication in the Fourier domain using the FFT coefficient vector provided, which can also be directly pasted into the tool. By multiplying in the Fourier domain, virtually any shape of filter transformation curve can be achieved; hence, complicated combinations of band and low-pass filters can be built that don't distort the signal with phase delay.