Turn sensitive samples into a custom blocking regex
PromptShield's custom-rule feature blocks anything that matches your own regular expression. Paste a few examples of the data you want kept out of AI chats — employee IDs, ticket numbers, internal codenames — and we'll build the regex for you. Everything runs locally in your browser.
Tip: use fake example values, never real secrets. Samples are processed 100% client-side — nothing is uploaded.
Test it before you ship it
Add it to your browser in three steps
Generate
Paste 1–5 example values above and press Generate regex. Use dummy values that show the shape of the data — never real secrets.
Copy
Tweak the pattern if you like, confirm it catches your test text below, then hit Copy regex.
Paste into the extension
Open the PromptShield popup → your custom regex rule field → paste and save. If you enabled case-insensitive matching, set flag i there too.
See what else PromptShield blocks
API keys, credit cards, SSNs, connection strings and 20+ built-in patterns — plus your own custom rules.