Sether Shield — PII guard for AI chat

Catches personal data in your prompt before it reaches ChatGPT, Claude, or Gemini. 100% local, nothing leaves your browser.

Sether Shield is a free Chrome extension that helps you review and replace sensitive details in AI chat prompts before sending them. On enabled sites, it flags supported values, such as email addresses and API keys, as you type or paste. Review each finding, use partial masks, or choose realistic decoys while keeping the surrounding prompt useful. Choose which sites activate Shield, import a watchlist of sensitive terms, and add custom detection rules. You can also replace selected text inside a prompt through the right-click menu. Optional auto-redact runs after a two-second pause and is off by default. Restore originals in your prompt when needed. On supported AI reply interfaces, Response Guard can restore known replacements for local display or copy a reply with the original values. This requires the matching session mapping and recognizable replacements. Restoring values on the page makes them visible to that website. Detection and replacement run in your browser. No Sether account is required, and the extension does not upload prompts to Sether or send telemetry. Settings, rules, site choices, watchlist terms and recent replacement history persist in local browser storage. Restore mappings use browser-session memory and clear when the browser closes. Detection can miss information or flag text you meant to share. Review the prompt before sending. If pending findings remain, Shield pauses the first send; sending again with the same findings proceeds. Your chosen AI website receives the text you submit, and its own data practices apply.