promptShield — Offline Document Anonymizer

Free & 100% offline. Anonymize names, emails & IDs in your documents. Your files never leave your machine.

A privacy tool for professionals who use AI to do serious work — building a report, a legal brief, a financial analysis, a research paper, a thesis — with confidential documents they can't afford to leak. promptShield encodes the sensitive information in your files before you send them to ChatGPT, Claude or Gemini, then decodes the AI's response back to the real values. Every name, account number, client or case detail is swapped for a stable, reversible code — so the AI still understands your documents and produces useful analysis, but never sees a single real identifier. When the answer comes back, one step restores everything. A WORKFLOW, NOT A ONE-OFF • Work across many documents in a persistent file library — your project stays organized between sessions. • Bring in files (PDF, Word, Excel and more) or paste text directly — pasted content becomes a file in your library, handled the same way. • Consistent codes across every file: the same client or entity gets the same code everywhere, so cross-document analysis holds together. • Encode to prepare your files, decode to bring the AI's answer back to reality — a full round trip. 100% OFFLINE, BY DESIGN Everything runs inside your browser. Your files never leave your machine, never touch a server, nothing is uploaded. You can verify it yourself in the Network tab: zero requests while it works. WHO IT'S FOR Lawyers, accountants, financial advisors, healthcare and compliance professionals, consultants, and academic researchers — anyone whose documents carry information that must not reach a third-party AI. NEED MORE POWER? The full promptShield desktop app adds native performance, multi-client workspaces, multi-folder organization, batch detection across large sets of files, and additional AI detection language packs. Learn more at https://promptshield.ca Free forever, and offline by design. This extension opens the promptShield web app and shows a one-time welcome panel. It requests only the "storage" permission, used to remember the welcome was shown. No tracking, no analytics, no data collection.