PII Shield — redact PII in AI chats

Masks emails, cards, phone numbers and IDs in AI chat boxes before they leave your browser, and warns before you upload a file.

PII Shield masks personal data in AI chat boxes before it leaves your browser. Type an email address, a card number, a phone number or an ID into a chat and PII Shield replaces it with a placeholder like [EMAIL_1] on its way out. The AI sees the placeholder. You see the real value in the reply, restored in place, so the conversation still reads normally. Detection runs locally, in the page. PII Shield is a workspace tool. You activate it with a workspace key, and it is usually provided by an employer. Read "What your workspace can see" below before you install it, it matters. ATTACHING A FILE A file is different, and we say so plainly: a scanned PDF or an image cannot be read in the browser, so we do not pretend to check it. Attach one and PII Shield stops it before the site receives it, tells you it has NOT been scanned, and offers to redact the document first. You can still upload it, that is your call but you make it knowingly. If you have already redacted a file with PII Shield, it recognises it and says so and it will warn you if you are about to upload the ORIGINAL by mistake instead of the redacted copy. CHECKING YOUR PAST CHATS There is a "Scan my Claude history" button in the popup. It reads the conversations already in your Claude account, looks for personal data you sent before PII Shield was protecting you and lists what it finds. The conversation text is read in your browser and is not sent to us. If your workspace has enabled it, this scan also runs on its own, in the background, at most once a day while you have Claude open. Your workspace administrator controls that setting, not us. If you would rather it did not, ask them to turn it off, or remove the extension. WHAT YOUR WORKSPACE CAN SEE Personal data that PII Shield finds; whether it masked it, or found it in an old chat, is recorded in a Leak Audit that the owner and administrators of your workspace can see. If your employer gave you the key, your employer can see it. That is the point of the product: it exists so an organisation can find out what personal data is reaching AI tools. What they get is the value itself, encrypted in your browser to a key only your workspace holds, plus which site and when. We cannot read it. Your chat messages are not sent to us, and neither are your files. WHAT IT COVERS Emails, credit and debit cards, phone numbers, national IDs and social security numbers, bank accounts (IBAN), IP and MAC addresses, crypto wallet addresses, street addresses, dates of birth, and names. You can add your own always-mask terms and your own patterns. A workspace key is required, and PII Shield fails closed: with no valid key it blocks a message carrying personal data rather than letting it through unprotected. Usage counts against your workspace's plan. HONEST LIMITS Automated detection is not perfect and is not a guarantee. It can miss things. Always review what you send to an AI. PII Shield reduces risk; it does not remove it. Supported sites: https://piishield.ai/extension#supported-sites Privacy policy: https://piishield.ai/privacy