Read between
the frequencies.

Your impedance spectrum. Your circuit. A clearer view of what lies beneath.

Ready to start · calculations run on your device

01 / SPECTRUMLOCAL ONLY

Bring your data.

↥Choose a spectrumCSV, TXT, TSV, DAT, ASC or DTA · up to 2 MB

DelimiterDecimal

Invert Z″ after import

No spectrum loaded.

Import audit & data preview

Your column mapping and sign convention will appear here.

f / Hz	Z′ / Ω	Z″ / Ω

02 / CIRCUIT19 MODELS

Choose a hypothesis.

Randles, CPE, diffusion, Gerischer, transmission lines and inductive models.

Parameter	Start / fixed	Lock

Bounds & fitting settings

WeightingLossOptimizerMulti-startMax evaluations / start

Minimum f / HzMaximum f / Hz

Positive parameters use log coordinates. Bounds stay inside the desktop engine’s allowed ranges.

Compare candidate models

Comparison uses automatic starts and original bounds for each candidate. Parameter locks and edited starts apply to a single fit.

A PRIVATE WORKSPACE

Files and fits stay in this browser. Nothing is uploaded. Save a project file to keep your work or move it to another device.

Open project ↥

The scientific runtime downloads once, then uses the browser cache. Closing or refreshing clears unsaved work.

THE RESPONSE

Every point has a story.

MeasuredFittedHover a point to inspect its frequency

⌁

A spectrum of possibilities.

Launch the lab, then import your data or try the demo.

Nyquist plots use Z′ against −Z″ in ohms with equal axis scaling.

03 / INTERPRETATION

The numbers behind the curve.

Fit a circuit to see parameters, uncertainty and residual statistics.

LOOK A LITTLE DEEPER

Signals, with context.

EXPLORATORY

Import a spectrum to view frequency coverage and diffusion screening.

Distribution of relaxation times

Regularization λ

Exploratory nonnegative Tikhonov inversion. Check sensitivity to λ before interpreting peaks.

Circuit ranking and diffusion screens guide interpretation; they do not prove a unique mechanism. Pseudo-χ² uses impedance modulus normalization, not measured variances. Uncertainty is a local linear approximation. This workspace does not perform formal Lin-KK validation.

IF THIS HELPS YOUR RESEARCH

Give the method its credit.

Built with the original EIS Gold Studio v1.13.2 scientific engine by Ali Afruz and Maryam Kaffash Jamshid. Please cite the archived release when you use it.

10.5281/zenodo.23154102 ↗

Citation & desktop edition ↗MIT license

Web adapter v1.0 · core pinned to commit 697fc2ff759c. Desktop batch, Mott–Schottky and visual circuit composition are available in the desktop edition.