Does BioSignal Workstation upload my data to a server?
No. All signal processing runs locally in your browser using Web Workers. Your CSV, TXT, and spreadsheet files are not uploaded to BioSignal Workstation servers.
Free Online BioSignal Analyzer for EEG, ECG, and EMG CSV Files
Upload a biosignal file
Drag and drop your file here, or choose a file from your device.
CSV
TXT
XLSX
XLS
ECG, EEG, EMG, and EOG samples are processed locally in your browser.
Demo: 3 channels, 10 seconds, 500 Hz. No file needed.
filename.csv
CSV
File ready
Parsing file…
Data Preview
No numeric data found. Please check your file format.
Preview Heuristics not research-grade QC
Residual dB is a moving-average residual heuristic, not physiological SNR. Hover each metric for the exact formula and caveats.
Channel
Residual dB
Clip%
Flatline%
Edge Δmean
Configure & Analyze
|
Load a file to see channels
Set a filter preset per channel:
Hz
⚠ High-pass cutoff < 1 Hz: Edge artifacts may occur in short signals due to filter transients.
Detected Hz from column
Global filters are overridden by per-channel settings above.
Filters ⓘ
High-Pass
Removes baseline wander & DC offset
Low-Pass
Removes high-freq noise & EMG artefacts
Notch
Removes powerline interference
Zero-phase filtering runs forward and backward. High-pass, low-pass, and notch cutoffs are mathematically pre-compensated so the final double-pass response precisely matches the cutoff frequencies and bandwidths you enter.
Starting DSP…
Zero-phase Butterworth filter · LTTB downsampling · all local
Nonuniform Timestamps Detected
Missing Samples Detected — PSD Results Limited
Signal Chart
Scroll to zoom · Drag to pan · Pinch on mobile
Generic local-extrema finder only. These counts are not validated R-peaks, spikes, bursts, or onset events.
The time-domain chart panel displays filtered and raw signal waveforms with zoom and pan controls. Use the toolbar buttons above to toggle layout, reset zoom, export PNG, detect extrema, select ROI, or measure intervals.
Measure:
Δt =
t₁ =
t₂ =
ROI Analysis
| Channel | Min | Max | Mean | Median | Std Dev | RMS | P-P | Energy | Duration |
|---|
Signal Statistics
Computed on the active analysis signal| Channel | Min | Max | Mean | Median | Std Dev | RMS | P-P | Energy | Duration |
|---|
Frequency Analysis (PSD)
Linear PSD compresses high-frequency content for
biosignals — a flat line above a few Hz is normal.
Switch to PSD — dB to see the full spectrum.
The PSD chart shows frequency-domain power density for the selected channel. Use the controls above to toggle linear, dB, or amplitude scales and select the PSD window length.
Band Summary
Spectrogram Time-Frequency Analysis
Select a channel and click Render
The spectrogram displays how signal frequency content evolves over time for the selected channel, with a colorbar indicating power or amplitude.
0 s
Time (s)
— s
Low - Hz
Displayed frequency
High - Hz
Export & Report
Finished your analysis?
A quick note helps us improve the workflow, exports, and reports.
Free Online BioSignal Analysis Workstation
The BioSignal Workstation is a comprehensive, free online tool designed for visualizing and exploring physiological signal data directly in your browser. Whether you are working with EEG, viewing an ECG (Electrocardiogram), or inspecting EMG data, this browser-based biosignal toolkit provides research-oriented exploratory functions without the need for expensive software installations.
100% Client-Side Processing for Total Privacy
Medical and physiological signal data requires careful handling. Unlike many cloud-based platforms, the BioSignal Workstation runs entirely locally on your device via HTML5 and JavaScript Web Workers. Your CSV or TXT signal data is not uploaded to BioSignal Workstation servers. This privacy-first design reduces exposure risk while giving you a rapid, offline-capable analysis experience.
Zero-Phase Butterworth Filtering
Reducing components such as powerline interference or baseline wander is a common step in biomedical signal processing. The tool implements forward-backward, zero-phase IIR Butterworth filtering to avoid ordinary causal filter delay in the interior of the signal. Filtered edges and analysis settings should still be interpreted with care.
Fast Fourier Transform (FFT) & Power Spectral Density (PSD)
Explore the frequency domain of your physiological inputs with built-in Fast Fourier Transform (FFT) capabilities. The analyzer calculates and plots the Power Spectral Density (PSD), allowing you to inspect EEG frequency-band activity such as alpha, beta, and gamma ranges or review mean/median frequency summaries in EMG signals.
Time-Frequency Analysis: Interactive Spectrograms
Observing how a signal's frequency content changes over time can support exploratory review of transient patterns. The spectrogram view uses the Short-Time Fourier Transform (STFT) to help inspect time-frequency structure in EEG examples or track changing EMG frequency content locally.
BioSignal Workstation FAQ
What file formats does BioSignal Workstation support?
BioSignal Workstation supports CSV (.csv), text (.txt), and Excel (.xlsx, .xls) files. The tool detects column headers and can help identify the sampling frequency.
What is the difference between Welch PSD and FFT in the tool?
The raw FFT shows frequency components across the selected signal block. Welch PSD averages windowed segments, reducing noise variance and making EEG bands or other dominant frequencies easier to inspect.
Can I use this for my research paper?
Yes. The tool uses standard signal-processing methods, including zero-phase Butterworth filtering, and lets you export processed data or a PDF report for research and educational workflows.