Fourier Transformation Tool

Description
📊 FFT Signal Analyzer — Interactive HTML ToolBy Data'sOk


Find the hidden cycles in any time series — no Excel add-ins, no macros, nothing to enable.Every dataset with a time component has cycles buried in it: seasonality in sales, resonance in a vibration sensor, a recurring pattern in web traffic. A Fast Fourier Transform (FFT) finds them — but most Excel-based FFT tools depend on the Analysis ToolPak add-in, which isn't on by default, doesn't work in Excel Online, and is unreliable on Mac. This tool doesn't have that problem: it's a single self-contained HTML file with its own FFT engine built in JavaScript. Open it in any browser, on any device, and it just works.


WHAT YOU GET
A single interactive HTML file, fully unlocked:
📥 Flexible data input — paste one value per line, paste "time,value" pairs for irregular sampling, upload a CSV/TXT file, or start from one of three built-in sample datasets (retail sales seasonality, a machine vibration sensor, an audio tone mix).
📉 Automatic trend removal — a rising or falling trend (like growing sales) can bury a real seasonal cycle in the spectrum. One click removes it before analysis and adds it back for the reconstructed signal, so you see the real pattern, not an artifact.
🎚️ Windowing functions — Hann, Hamming, and Blackman windows to reduce spectral leakage, with plain-English guidance on when to use each.
📊 Live time-domain and frequency-spectrum charts — see your signal and its spectrum side by side, redrawn instantly as you change settings.
🎯 Automatic cycle detection — the dominant frequencies are found and labeled for you, with frequency, period, magnitude, and share of total signal energy, so you don't have to eyeball a chart to find the peak.
🔧 Noise filter / cycle isolation — rebuild your signal using only its strongest frequency components with a single slider. A fast, visual way to denoise data or isolate one specific recurring cycle.
🔊 Sonify your data — play any dataset as audio, a genuinely useful sanity-check for vibration and audio-style signals (and just fun on anything else).
⬇️ CSV export — download the full spectrum or the filtered/reconstructed signal for use elsewhere.
📖 Included user manual — a plain-English walkthrough of every option and how to read the results.


WHO IT'S FOR
→ Analysts and category managers checking for seasonality in sales, demand, or web traffic→ Engineers and technicians reviewing vibration or sensor data for dominant frequencies→ Anyone who has tried an Excel FFT tool before and hit an Analysis ToolPak error→ Students and researchers who want a working FFT without setting up software→ Consultants who need a fast, presentable frequency analysis for a client.


WHY IT'S DIFFERENT
Most FFT tools on this marketplace are Excel files that quietly depend on an add-in most buyers don't have enabled — the single most common way an FFT template fails after purchase. This tool has no such dependency: it's real JavaScript running in your browser, tested against known signals for accuracy. It also goes further than a bare FFT — automatic peak labeling and one-click noise filtering are features you won't find in a plain spreadsheet version.No subscription. No software to install. No data uploaded anywhere — everything runs locally in your browser.


REQUIREMENTS
Any modern browser (Chrome, Edge, Firefox, Safari) on Windows, Mac, or Linux. No installation, no add-ins, no internet connection required after download.This Best Practice includes1 HTML file, 1 PDF/Word user manual.