GitHub

Privacy Policy

Last Updated: December 2025

Overview

Markdown Viewer (“the Extension”) respects and protects user privacy. This privacy policy explains how the Extension handles user information.

Our Commitment

The Extension does NOT collect, store, or transmit any personal user data.

We believe your documents are your business. Everything stays on your device.

Data Collection

The Extension does NOT collect:

Data Type Collected?
Personal identification ❌ No
Health information ❌ No
Financial information ❌ No
Authentication data ❌ No
Personal communications ❌ No
Location information ❌ No
Browsing history ❌ No
User activity ❌ No
Website content ❌ No
Document content ❌ No

Local Data Storage

The Extension uses browser’s local storage (Chrome Storage API / Firefox Storage API) to save the following information only on your device:

1. Rendering Cache

  • PNG images converted from Mermaid diagrams
  • Rendered Graphviz, Vega, and Infographic charts
  • Complex HTML/SVG content

Purpose: Improve loading speed when reopening documents.

2. User Settings

  • Document reading position (scroll position)
  • Zoom level settings
  • Page layout preferences
  • Theme selection

Purpose: Remember your preferences between sessions.

Important

  • ✅ All data stored locally only
  • ✅ Never uploaded to any server
  • ✅ You can delete anytime by clearing browser cache
  • ✅ Uninstalling removes all data

Permissions Explained

The Extension requests these permissions solely for core functionality:

storage & unlimitedStorage

Purpose: Cache rendered images and save user settings locally.

Not used for: Tracking, analytics, or data collection.

offscreen (Chrome only)

Purpose: Render Markdown content in the background, including converting diagrams to PNG images.

Not used for: Any external communication.

scripting

Purpose: Inject rendering scripts when opening Markdown files to convert Markdown to formatted HTML display.

Not used for: Accessing other websites or data.

tabs

Purpose: Detect if the current tab has opened a Markdown file, and get document title for export file naming.

Not used for: Tracking browsing history.

downloads

Purpose: Export Markdown documents to Word (.docx) format and save locally.

Not used for: Uploading files anywhere.

Host Permissions (file://, http://, https://)

Purpose: Access local Markdown files and online Markdown files (on GitHub, GitLab, etc.).

Not used for: Accessing any non-Markdown content.

Data Sharing

The Extension does NOT share user data with any third parties.

We:

  • ✅ Run completely locally
  • ✅ Include no analytics or tracking code
  • ✅ Use no remote servers
  • ✅ Make no external network requests
  • ✅ Send no data to any third parties

Data Security

Since the Extension does not collect or transmit any user data:

  • No risk of data breach
  • No server vulnerabilities
  • No third-party data exposure
  • All processing on your device

Third-Party Services

The Extension uses zero third-party services:

  • No analytics (Google Analytics, Mixpanel, etc.)
  • No error tracking (Sentry, Bugsnag, etc.)
  • No advertising networks
  • No external APIs
  • No CDNs for content

All code runs locally. All dependencies are bundled.

Open Source Transparency

The Extension is fully open source under the ISC license.

You can:

  • View all source code
  • Audit for privacy concerns
  • Build from source yourself
  • Verify our claims

Repository: github.com/markdown-viewer/markdown-viewer-extension

User Rights

You can at any time:

Clear Local Data

  1. Go to browser settings
  2. Find extensions storage
  3. Clear Markdown Viewer data

Remove All Data

  1. Uninstall the Extension
  2. All local storage is automatically deleted

Manage Permissions

  1. Go to chrome://extensions/ or about:addons
  2. Find Markdown Viewer
  3. Adjust permissions as needed

Children’s Privacy

The Extension:

  • Is not directed to children under 13
  • Does not knowingly collect information from children
  • Has no age-restricted features
  • Processes no personal data from any user

International Users

Since no data is collected or transmitted:

  • No GDPR data transfers
  • No cross-border data issues
  • Same privacy for all users worldwide

Policy Changes

If there are any changes to this privacy policy:

  1. We will update this page
  2. Modify the “Last Updated” date
  3. Post a notice in the GitHub repository

Users are encouraged to review this policy periodically.

Contact

For any questions about this privacy policy:

Summary

Question Answer
Do you collect my data? No
Do you track my activity? No
Do you share data with third parties? No
Is my data uploaded anywhere? No
Is the code auditable? Yes, it’s open source
Can I delete my local data? Yes, anytime

Your privacy is 100% protected.