Free Online COMTRADE Viewer
Upload .cfg/.dat or .cff files and get interactive waveforms, phasor diagrams, protection analysis, and 40+ computed signals — all in your browser, completely free.
Everything you need to analyze a fault
Interactive Waveforms
Zoom, pan, and place dual A/B cursors on analog and digital channels. Measure RMS, peak, phase angle, and delta values between any two points.
Phasor Diagrams
See voltage and current phasors in real time as you scrub through the recording. Compare pre-fault and fault conditions with A/B cursor snapshots.
Protection Analysis
Five dedicated tabs: distance protection (R-X diagram with zones), overcurrent (IDMT curves), differential (bias characteristic), directional (torque angle), and fault location.
40+ Computed Signals
Create derived signals: RMS, power (P/Q/S), harmonics, sequence components, ROCOF, residual currents, DC offset, superimposed quantities, and more.
Built-in Report Editor
Compose professional fault analysis reports with 13 drag-and-drop block types. Add waveform charts, measurement tables, phasor snapshots, and narrative text. Export to PDF.
Cloud Storage & Sharing
Save recordings to your private cloud. Organize with folders and device tags. Generate read-only share links for colleagues — they can view without signing up.
Three Steps
Upload. Explore. Understand.
From raw COMTRADE data to a full fault report — no installs, no hassle.
Drop your files
Drag and drop .cfg + .dat or .cff files. Parsing is instant — everything runs client-side.
Explore the data
Interactive waveforms, phasor diagrams, harmonics, impedance plots, symmetrical components — all in one view.
Derive & Understand
Symmetrical components, impedance, power, harmonics, differential — computed locally and displayed in interactive tabs.
Supported formats
Detego handles every COMTRADE variant you'll encounter in the field — from legacy 1991 files off older IEDs to modern 2013 CFF archives from digital substations.
IEEE Revisions
- IEEE C37.111-1991
- IEEE C37.111-1999
- IEEE C37.111-2013
Data Formats
- ASCII
- Binary (16-bit integer)
- Binary32 (32-bit integer)
- Float32 (IEEE 754)
File Types
- .cfg + .dat (separate pair)
- .cff (unified format)
- Up to 250 MB per file
- All major IED manufacturers
How Detego compares
| Feature | DetegoThis tool | SIGRA | TransView | WaveWin | OscilloViewer |
|---|---|---|---|---|---|
| Price | Free | Paid | Paid | Free | Free |
| Platform | Web | Desktop | Desktop | Desktop | Web |
| Phasor / Vector Diagrams | |||||
| Impedance / Zone Plots | |||||
| Fault Location | |||||
| Computed Signals | 40+ | ||||
| Report Builder | |||||
| Cloud Sharing | |||||
| AI Analysis | |||||
| No Install Required |
Comparison based on publicly available feature lists as of March 2026.
Frequently asked questions
Ready to analyze a recording?
Upload a COMTRADE file and get results in seconds. Free, no account needed.
Free to start — no account required