LLM Guard — Privacy Policy
Last updated: 15 June 2026
LLM Guard is a browser extension that anonymizes or blocks personal and sensitive data in the prompts you send to AI chat services such as ChatGPT, Claude, Gemini and Copilot. It is designed to protect your data, not to collect it.
What the extension does
On the supported AI chat websites, LLM Guard inspects the text of the
prompt you are about to send. It applies a set of detection rules to find
sensitive data (for example email addresses, phone numbers, API keys, or
keywords your organization has configured). Depending on the matching
rule, it either replaces the sensitive value with a reversible placeholder
such as [EMAIL_a1b2], warns you, or blocks the request. All
of this happens inside your browser, in real time.
What data is processed, and where
All processing is performed locally in your browser. No prompt content, detected value, or browsing activity ever leaves your device.
| Data | Purpose | Where it lives |
|---|---|---|
| Prompt text on supported AI sites | Read in-memory to detect and anonymize sensitive data before the prompt is sent | In page memory only — never stored, never transmitted |
| Placeholder ↔ real-value map | Lets you manually reveal the real values again in the page | Kept in the page session; discarded when the tab is closed |
| Detection rules & settings | Your configuration (the rules and the on/off switch) | chrome.storage.sync on your device / your Google profile |
| Local activity log & counters | Shows recent detections in the popup so you can see what was caught | chrome.storage.local on your device only |
What we do not do
- We do not send your prompts or detected values to any server.
- We do not collect analytics, telemetry, or usage statistics.
- We do not use cookies or advertising identifiers.
- We do not sell or share any data with third parties.
- We do not require an account or any sign-in.
Permissions and why they are needed
| Permission | Why |
|---|---|
| Access to supported AI chat sites | To read and protect the prompt before it is sent on those sites |
storage |
To save your rules and settings locally |
scripting |
To keep protection active on already-open tabs after the extension updates |
alarms |
To reset the toolbar badge counter once a day |
Data retention and removal
Your rules, settings, and local activity log remain on your device until you clear them or uninstall the extension. Uninstalling LLM Guard removes all of its locally stored data. Because nothing is sent to a server, there is no remote copy to delete.
Children's privacy
LLM Guard is a general-purpose privacy tool and is not directed at children. It collects no personal information from anyone.
Changes to this policy
If this policy changes, the updated version will be posted on this page with a new "last updated" date.
Contact
Questions about this policy or the extension can be sent to gauthier.robert2@gmail.com, or raised on the project's GitHub repository.