Blackpen — Privacy Policy

Last updated: July 15, 2026

Blackpen is a browser extension that anonymizes personally identifiable information (PII) in AI chat composers. It detects sensitive values in the message you are about to send, replaces them with placeholder tokens so the AI model never receives the real values, and re-identifies the placeholders on your screen so you keep seeing your own data.

The short version

Everything happens on your device. Blackpen collects nothing and transmits nothing.

What Blackpen processes, and where

• The text of the message you write in a supported AI chat composer (chatgpt.com, chat.openai.com, claude.ai, gemini.google.com) is analyzed locally in your browser by a machine-learning model that ships inside the extension package. No text is ever sent to Blackpen, to any server, or to any third party.
• The mapping between placeholder tokens and your real values (the “vault”) is stored in your browser’s local extension storage (chrome.storage.local) on your device only. It is never synced or transmitted. You can delete it at any time from the extension popup, or by uninstalling the extension.
• Your preferences (on/off switch, display mode) are stored in the same local storage.

What Blackpen does not do

• No data collection, no telemetry, no analytics.
• No accounts, no sign-in.
• No network requests at runtime: the detection model is bundled with the extension and explicitly configured never to contact external servers.
• No selling or sharing of any data with third parties — Blackpen has no data to sell or share.

Permissions

• storage — keeps your local vault and preferences on your device.
• activeTab — lets the popup show the protection status of the AI chat tab you are viewing.
• offscreen — hosts the bundled detection model, which cannot run inside the extension’s service worker for technical reasons.
• Host access to the four supported AI chat sites — allows the extension to read and modify the message composer on those sites in order to mask and reveal values. It has no access to any other website.

Changes to this policy

If a future version of Blackpen ever changes how data is handled, this policy will be updated before that version is released, and the change will be reflected in the extension’s store listing.

Contact

Questions about this policy: vancoweb.design@gmail.com