Privacy Policy

Last updated: March 5, 2026

Overview

Koenji Lab provides free browser-based developer tools. We are committed to protecting your privacy. All tools on this site process data entirely in your browser using JavaScript and WebAssembly — no files, inputs, or results are ever sent to our servers.

No AI Training

Your data is never used to train AI models or machine learning systems. We do not collect, store, or share any data you input into our tools. Everything you process on Koenji Lab stays on your device and is discarded when you close the page.

Data Collection

We do not collect, store, or transmit any personal data or user-uploaded files. Your files (such as HEIC images) and text inputs (such as JSON, cron expressions, or search queries) are processed locally in your browser and never leave your device. You can verify this by inspecting the Network tab in your browser's developer tools.

Third-Party APIs

Some tools (such as Person Age Timeline) make requests to public APIs including Wikipedia and Wikidata directly from your browser. These requests are subject to the privacy policies of those services. We do not proxy or log these requests.

Cookies & Analytics

We do not use tracking cookies or analytics services. If advertising is enabled in the future via Google AdSense, Google may use cookies to serve ads based on your browsing history. You can opt out of personalized advertising at Google Ads Settings.

External Links

Our site may contain links to external websites. We are not responsible for the privacy practices of those sites.

Changes

We may update this policy from time to time. Changes will be posted on this page with an updated date.

Contact

If you have questions about this policy, please reach out via our Contact page.