Privacy Policy

Claude Fact Checker Chrome Extension — Effective March 1, 2026

1. What This Extension Does

Claude Fact Checker lets you select text on webpages and send it to the Claude AI API (operated by Anthropic, PBC) for fact-checking analysis. The results are displayed directly in your browser.

2. Data Collected

This extension collects and processes two types of data:

a) API Key: Your Anthropic API key, which you enter in the extension settings. This is stored locally in Chrome's synced storage (chrome.storage.sync) and is only used to authenticate requests to the Anthropic API. It is never sent anywhere other than api.anthropic.com.

b) Selected Text: When you use the fact-check feature, the text you select on a webpage is sent to the Anthropic API (api.anthropic.com) for analysis. This text is not stored by the extension after the analysis is complete.

3. Data Not Collected

This extension does not:

• Collect browsing history or URLs
• Track your activity across websites
• Use analytics, telemetry, or tracking scripts
• Store or log the text you fact-check
• Collect any personal information beyond your API key
• Share data with any party other than Anthropic

4. Third-Party Data Sharing

Selected text is sent to Anthropic's Claude API for analysis. Anthropic's handling of this data is governed by their privacy policy.

No other third parties receive any data from this extension.

5. Data Storage and Security

• Your API key is stored using Chrome's built-in chrome.storage.sync API, which encrypts data at rest and syncs across your signed-in Chrome browsers.
• Selected text is held in memory only during analysis and is not persisted to disk or any database.

6. Your Rights

• You can delete your stored API key at any time by clearing it in the extension settings or uninstalling the extension.
• Uninstalling the extension removes all locally stored data.
• No account or registration is required to use this extension (beyond your own Anthropic API key).

7. Changes to This Policy

We may update this privacy policy from time to time. The effective date at the top of this page indicates when the policy was last revised.

8. Contact

For questions about this privacy policy, visit github.com/son1112.