Privacy Policy

Last Updated: February 13, 2026

Introduction

Reading Copilot ("we," "our," or "us") is committed to protecting your privacy. This Privacy Policy explains how we collect, use, disclose, and safeguard your information when you use our Chrome extension and related services.

By using Reading Copilot, you agree to the collection and use of information in accordance with this policy. If you do not agree with our policies and practices, please do not use our extension.

Information We Collect

Information You Provide

  • Vocabulary Words: When you click on words or phrases while reading, we collect the specific word/phrase you selected for vocabulary lookup.
  • Sentence Context: To provide accurate contextual meanings, we collect the current sentence containing the word, as well as the previous and next sentences for context analysis.
  • Article Information: When you save vocabulary words, we may collect the URL and title of the article you were reading (stored locally on your device).
  • User Preferences: We store your preferences such as font size, line height, theme settings, and explanation language preference locally on your device.

Anonymous User Identifier

To track usage patterns and improve our service, we generate a unique anonymous identifier (UUID) locally on your device when you first use the extension. This identifier:

  • Is generated randomly and stored only on your device
  • Cannot be used to identify you personally
  • Is sent with API requests to help us track usage and costs
  • Is associated with usage records stored in our database

Usage Records

When you look up words using our service, we store the following information in our database:

  • Your anonymous user identifier (UUID)
  • The word or phrase you looked up
  • Sentence context (current, previous, and next sentences)
  • The explanation language preference
  • LLM response data (meaning, examples, similar words, etc.)
  • API usage metrics (token counts, costs) for service optimization
  • Timestamp of the lookup

This data is used to improve our service quality, track API costs, and analyze usage patterns. It cannot be used to identify you personally.

Information We Do NOT Collect

  • We do not track or store your browsing history
  • We do not collect personal identification information (name, email, etc.) unless you explicitly opt into cloud sync features
  • We do not track which websites you visit
  • We do not collect data about your general web browsing behavior
  • We do not use cookies or tracking technologies

How We Use Your Information

  • Vocabulary Lookup: We use the words/phrases and sentence context you provide to generate contextual explanations using AI technology. This data is sent to our backend API for processing.
  • Local Storage: Your vocabulary words, preferences, and cached explanations are stored locally on your device using Chrome's storage API.
  • Performance Optimization: We cache LLM responses locally to improve response times and reduce API calls for frequently looked-up words.
  • Service Improvement: We may use aggregated, anonymized data to improve our service quality and accuracy (no personal identifiers are included).

Data Storage and Security

Local Storage (Default)

By default, all your vocabulary data and preferences are stored locally on your device using Chrome's storage API. This data never leaves your device unless you explicitly choose to sync it to the cloud (a future feature that requires separate consent).

Data Transmission

When you look up a word meaning, the following information is transmitted to our backend API:

  • Your anonymous user identifier (UUID) - generated locally on your device
  • The specific word or phrase you clicked
  • The current sentence containing the word
  • The previous and next sentences (for context)
  • Your preferred explanation language

Important: We do not send your browsing history, article URLs, or personal information (name, email, etc.) with these API requests. The user identifier is an anonymous UUID that cannot be used to identify you personally.

Security Measures

  • All API communications use HTTPS encryption
  • Usage records are stored securely in our database with anonymous user identifiers only
  • We do not store personal information or browsing history
  • Local data is protected by Chrome's built-in security mechanisms
  • We follow industry-standard security practices
  • Database access is restricted and encrypted

Third-Party Services

Reading Copilot uses the following third-party services:

Anthropic Claude API

We use Anthropic's Claude API to generate contextual word explanations. When you look up a word, the word/phrase and sentence context are sent to Anthropic's servers for processing. Please review Anthropic's privacy policy.

We do not share any personal information with Anthropic. Each API request contains only the word/phrase and sentence context needed for explanation generation. We track API usage (token counts, costs) on our backend for service optimization, but this data is associated only with anonymous user identifiers.

Chrome Extension Permissions

Reading Copilot requires the following Chrome extension permissions:

  • activeTab: Allows us to access the current tab's content only when you activate the extension. We use this to extract text and wrap words for vocabulary lookup.
  • storage: Enables local storage of your vocabulary words, preferences, and cached explanations on your device.
  • scripting: Allows us to inject content scripts that make words interactive and display the vocabulary overlay UI.
  • Host Permissions (<all_urls>): Required because the extension works on any website you visit. We only access page content when you explicitly activate the extension.

We do not use remote code. All JavaScript code is bundled and included directly in the extension package. No external scripts are loaded from remote servers.

Your Rights and Choices

  • Access Your Data: You can view all your saved vocabulary words through the extension sidebar.
  • Delete Your Data: You can delete individual vocabulary words or clear all data at any time through the extension interface.
  • Export Your Data: You can export your vocabulary collection for backup or use in other applications.
  • Disable the Extension: You can disable or uninstall the extension at any time through Chrome's extension settings. This will stop all data collection.
  • Control Preferences: You can modify your preferences (font size, theme, language) at any time through the extension options page.

Data Retention

  • Local Data: Your vocabulary words and preferences are stored locally on your device until you delete them or uninstall the extension.
  • API Requests: We store usage records in our database associated with anonymous user identifiers. These records include the word/phrase looked up, context sentences, LLM responses, and API usage metrics (token counts, costs). API responses are also cached locally on your device for performance.
  • Usage Records: Usage records are retained indefinitely for service improvement and cost tracking purposes. They are associated only with anonymous user identifiers and cannot be used to identify you personally.
  • Cloud Sync (Future Feature): If you opt into cloud sync in the future, you will be able to delete your cloud-stored data at any time through your account settings.

Children's Privacy

Reading Copilot is not intended for children under the age of 13. We do not knowingly collect personal information from children under 13. If you are a parent or guardian and believe your child has provided us with personal information, please contact us so we can delete such information.

Changes to This Privacy Policy

We may update this Privacy Policy from time to time. We will notify you of any changes by posting the new Privacy Policy on this page and updating the "Last Updated" date. You are advised to review this Privacy Policy periodically for any changes.

Changes to this Privacy Policy are effective when they are posted on this page.

International Users

If you are using Reading Copilot from outside the United States, please note that your information may be transferred to, stored, and processed in the United States where our servers are located. By using our service, you consent to the transfer of your information to the United States.

If you are located in the European Economic Area (EEA), you have certain data protection rights under the General Data Protection Regulation (GDPR). Since we primarily store data locally on your device and do not collect personal identifiers, most GDPR rights are already satisfied by our privacy-first design. If you have questions about your rights, please contact us.

Contact Us

If you have any questions about this Privacy Policy or our data practices, please contact us:

  • Email: You can reach us through the support page in the extension or visit our support page on our website.
  • Extension Support: Use the "Support" option in the extension sidebar menu.

Summary

Reading Copilot is designed with privacy as a core principle:

  • ✅ All vocabulary data is stored locally on your device by default
  • ✅ We do not track your browsing history or which websites you visit
  • ✅ We do not collect personal identification information (name, email, etc.)
  • ✅ We use anonymous user identifiers (UUIDs) for usage tracking - cannot identify you personally
  • ✅ Only the words/phrases you click and sentence context are sent to our API for processing
  • ✅ Usage records are stored securely and used only for service improvement
  • ✅ You have full control over your local data - view, export, or delete at any time
  • ✅ No remote code execution - all code is bundled in the extension