DEWFOG
License, Security & Support

About Dewfog

Everything you need to know about how the tool works, what data it touches, and how to get help.

01

Security & privacy

Dewfog has no backend. Every calculation — probability estimation, Monte Carlo simulation, loss exceedance curve — runs entirely in JavaScript inside your browser. Your inputs and results never leave your device.

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No data transmission The page enforces connect-src: none in its Content Security Policy. This directive instructs the browser to block every outbound network request — including analytics, beacons, and API calls. You can verify this yourself: open DevTools → Network tab, run the model, and observe that no requests are made.
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No persistent storage Nothing is written to localStorage, sessionStorage, cookies, or IndexedDB. Closing the tab discards all inputs and results.
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No account, no tracking There is no sign-up, no login, and no analytics script. The tool loads, runs, and closes without recording that you were ever there.
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Verifiable open source The full source code is published on GitHub. You can audit every line of the model and confirm that no hidden behaviour exists.
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Subresource integrity The two external libraries used (Chart.js and SheetJS) are loaded from a CDN with cryptographic SHA-384 hashes. If the CDN serves a modified file the browser refuses to execute it.

The Compare page reads .xlsx files through the browser's FileReader API. Files are parsed in memory and never uploaded anywhere — connect-src: none makes server transmission technically impossible on that page too.

02

License & usage

Dewfog is free to use with no account, no usage limits, and no time restrictions. The source code is open and published on GitHub.

  • Use the tool for any purpose — personal, commercial, academic, or internal risk assessments.
  • Export results and include them in reports, presentations, or board papers.
  • The model is a screening and prioritisation tool. For decisions requiring rigorous probabilistic treatment — capital reserves, insurance limits — the output should be validated against more comprehensive methods.
View source on GitHub ↗
03

Support

Dewfog is provided free of charge. Support is available on a best-effort basis — there are no guaranteed response times or SLAs.

Bug reports & feature requests

Open an issue on GitHub. This is the best way to report a problem or suggest an improvement — it keeps a public record and lets others follow along.

Open an issue ↗
Direct contact

For questions not suited to a public issue — methodology questions, feedback, or anything else — you can reach us by email. Responses are best-effort and may take a few days.

Email