PII Shield — AI Privacy Guard

Tracking since May 26, 2026.

Changelog

• Jun 8, 2026
  description

  PII Shield is a privacy-first browser extension that monitors your AI chat sessions in real time, alerting you before sensitive personal information is accidentally shared with an AI tool.
  
  HOW IT WORKS As you type, PII Shield scans your input entirely within your browser using a combination of precise pattern-matching rules and a locally-running AI model. Nothing is ever sent to a server. No data leaves your device.
  
  WHAT IT DETECTS • Names, organisations and locations (AI-powered contextual detection) • Email addresses and phone numbers • UK National Insurance numbers and NHS numbers • Credit and debit card numbers (with Luhn validation) • Bank sort codes and account numbers • UK postcodes and dates of birth • IP addresses
  
  WHEN PII IS FOUND • A warning toast appears at the bottom of the page • The detected text is highlighted inline • A detailed side panel lists all findings by severity (High / Medium / Low) • The extension badge shows a count of active detections
  
  PRIVACY FIRST PII Shield runs a 27 MB on-device neural network — no GPU required, no cloud service, no API calls, and no telemetry. Everything stays in your browser tab. It only activates on the AI sites you have enabled it for and does not run in the background on other websites.
  
  PERMISSIONS EXPLAINED • storage — saves your on/off preferences locally; no PII is ever stored • sidePanel — shows the findings panel on the right side of your browser • activeTab — allows the extension to interact with the currently active tab when you use the keyboard shortcut

  PII Shield is a privacy-first browser extension that monitors your AI chat sessions in real time, alerting you before sensitive personal information is accidentally shared with an AI tool.
  
  HOW IT WORKS
  As you type, PII Shield scans your input entirely within your browser using precise pattern-matching rules. Nothing is ever sent to a server. No data leaves your device.
  
  WHAT IT DETECTS
  • Email addresses and phone numbers (global & international formats)
  • UK National Insurance numbers and NHS numbers
  • Credit and debit card numbers (with Luhn validation)
  • Bank sort codes and account numbers
  • UK postcodes and dates of birth
  • IP addresses and street addresses
  • Full names with titles
  
  WHEN PII IS FOUND
  • A warning toast appears at the bottom of the page
  • The detected text is highlighted inline
  • A detailed side panel lists all findings by severity (High / Medium / Low)
  • The extension badge shows a count of active detections
  
  PRIVACY FIRST
  All scanning happens entirely in your browser. No GPU, no cloud service, no API calls, and no telemetry. Everything stays in your browser tab. It only activates on the AI sites you enable and does not run in the background on other websites.
  
  PERMISSIONS EXPLAINED
  • storage — saves your on/off preferences locally; no PII is ever stored
  • sidePanel — shows the findings panel on the right side of your browser
  • activeTab — allows the extension to interact with your current tab

Permissions & access

Permissions

storagesidePanelactiveTab

Host access

https://chat.openai.com/*, https://chatgpt.com/*, https://claude.ai/*, https://gemini.google.com/*, https://copilot.microsoft.com/*, https://www.bing.com/*, https://www.perplexity.ai/*, https://huggingface.co/*, https://grok.com/*, https://x.com/*

Screenshots