PPolySim OS

Fourier Transform (FFT)

Any signal is a sum of frequencies. Compose one from a few tones and some noise, and the Fourier transform pulls those exact frequencies back out.

Fourier Transform (FFT)Live

Controls

Build a signal from a few sine tones plus noise, and the discrete Fourier transform recovers exactly which frequencies are present — the foundation of all signal processing.

Presets

▶ Run in Python

Data Inspector

Samples256
Peaks at4, 9
TransformDFT

Governing equation

Reading this result: The FFT splits this 2-tone signal into bins: each input sinusoid at 4, 9 appears as a distinct spike, and with noise at 0 the baseline between them stays clean.

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How it works

The discrete Fourier transform converts a time-domain signal into its frequency spectrum, revealing which sinusoids it contains. It underpins audio, image, and radio processing, data compression, and nearly all of modern signal analysis.

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Frequently asked questions

Is this Fourier transform FFT tool really free?
Yes. Fourier Transform (FFT) runs entirely in your browser using your device's own compute, so local use is free forever. You only pay Compute Tokens if you scale a job to the cloud.
Do I need to install anything?
No. Everything runs client-side in a modern browser — no downloads, no license, no account required to start.
Can I save or share my simulation?
Create a free account to save projects, and use a shareable embed or minted DOI to publish a live, interactive version anywhere.
How accurate are the results?
The solver uses established numerical methods, but results are for research and educational purposes and should be validated against experiment or professional review before you rely on them.