Privacy Policy

What LanternKit does

LanternKit provides free developer tools that run in your browser. Most tools process data entirely on your device — your input never leaves your browser.

Data collected

LanternKit does not collect personal data. Specifically:

• No user accounts or sign-ups (currently).
• No analytics or tracking scripts.
• No cookies, except essential ones if introduced later.

How tools process your data

LanternKit tools fall into two categories:

Client-side tools

The majority of tools run entirely in your browser. Your input is never sent to any server. This includes: Data Format Converter, Markdown to HTML, UUID / ULID / NanoID Generator, HTTP Header Analyzer, Cron Expression Builder, JWT Decoder (decoding only), Regex Tester, Diff Viewer, UTM Builder, and JSON Schema Generator.

Proxy-backed tools

Six tools make network requests on your behalf via a Cloudflare Worker. When you use these tools, the URL, HTTP method, headers, and/or request body you provide are sent to LanternKit's server to perform the request:

• API Request Builder — sends your full request (URL, method, headers, body) to LanternKit's Worker, which forwards it to the target URL and returns the response.
• CORS Tester — sends the target URL and origin to LanternKit's Worker to perform a real preflight and actual request.
• JWT Fetcher (JWK lookup) — sends the JKU URL from a JWT header to LanternKit's Worker to fetch the matching public key.
• Open Graph / Social Card Preview — sends the target URL to LanternKit's Worker, which fetches the page HTML to extract meta tags.
• Robots.txt + Sitemap Validator — sends the target domain URL to LanternKit's Worker to fetch robots.txt or sitemap.xml.
• Redirect Checker — sends your URLs to LanternKit's Worker, which follows each redirect hop and returns the full chain.

Important: do not include API keys, passwords, or other secrets in requests made through proxy-backed tools unless you intend to transmit them. LanternKit does not store or log request payloads at the application level. Cloudflare infrastructure logs may include standard request metadata (IP addresses, request timestamps) per their standard logging practices.

Hosting

LanternKit is hosted on Cloudflare. Cloudflare may log standard request metadata (IP addresses, request timestamps) as part of their infrastructure. See Cloudflare's Privacy Policy for details.

Theme preference

Your light/dark theme preference is stored in your browser's local storage. This data never leaves your device and is not sent to any server.

Future changes

If LanternKit introduces features that require accounts, analytics, or server-side processing, this policy will be updated before those features go live. LanternKit will never retroactively change how your existing data is handled.

Contact

Questions about this policy? Reach out via the project's GitHub repository.