3MF to STL

Privacy Policy

Privacy policy for 3MF to STL, covering local browser file processing, analytics, cookies, third-party services, and how to contact us.
Dec 8, 2025

Introduction

Welcome to 3MF to STL, a free online 3D model file converter. At 3MF to STL, your privacy is of utmost importance to us. This privacy policy outlines how we handle your data when you use our conversion services.

Our Privacy Commitment

All file processing happens locally in your browser. We are committed to protecting your privacy with the following principles:

  1. No File Uploads to Servers: Your 3MF files never leave your device. All conversions are performed client-side in your browser using JavaScript.

  2. No Personal Data Collection: We do not collect, store, or process any personally identifiable information.

  3. No File Storage: We do not save, cache, or retain any of your uploaded files or converted STL outputs.

Information We Collect

Analytics Data (Optional)

To improve our service, we may collect anonymous usage analytics including:

  • Pages visited
  • Conversion success/failure rates (without file details)
  • Browser type and version
  • Approximate geographic location (country level)
  • Device type (desktop/mobile)

This data is aggregated and anonymized. It cannot be used to identify individual users.

Cookies

We use minimal cookies for:

  • Language Preference: To remember your selected language (English/中文)
  • Analytics: Third-party analytics services (Google Analytics, Plausible, Microsoft Clarity) may set cookies for usage tracking

You can disable cookies in your browser settings without affecting the core conversion functionality.

Data Storage and Security

Local Processing

All file processing occurs entirely within your browser:

  • Your 3MF files are processed using client-side JavaScript
  • Converted STL files are generated in your browser's memory
  • No data is transmitted to our servers during conversion
  • Files are automatically removed from browser memory after download

Website Security

  • We use HTTPS encryption for all website communications
  • Our website is hosted on secure cloud infrastructure
  • Regular security updates are applied to protect against vulnerabilities

Third-Party Services

We use the following third-party services for analytics only:

  1. Google Analytics: Tracks anonymous usage statistics
  2. Microsoft Clarity: Analyzes user interactions (anonymized)
  3. Plausible Analytics: Privacy-focused analytics with no personal data collection

These services may collect anonymous usage data according to their respective privacy policies. They do NOT have access to your 3MF or STL files.

Your Rights

You have the right to:

  • Use our service without creating an account or providing personal information
  • Disable analytics cookies while still using the conversion tool
  • Request information about any data we collect (contact us at the email below)

Children's Privacy

Our service does not target children under 13 years of age. We do not knowingly collect personal information from children.

Changes to This Policy

We may update this privacy policy from time to time. We will notify you of any material changes by updating the "created_at" date at the top of this policy. Continued use of the service after changes constitutes acceptance of the updated policy.

Contact Us

If you have questions about this privacy policy, please contact us:

Last Updated: December 8, 2025

Summary

TL;DR: Your files never leave your device. We don't collect personal data. All conversions happen locally in your browser. We only collect anonymous usage statistics to improve the service.