Privacy Policy

Last updated: June 15, 2026

1. Data controller

The data controller for Nabla Grader is Guillaume Bellec, who also serves as the Data Privacy Officer. For any questions or requests regarding your personal data, contact: contact@nabla-grader.com

2. Data we collect

We collect the minimum data necessary to operate the platform:

• Account data -- email address, name, and hashed password (or OAuth provider ID if using Google sign-in).
• Submission data -- uploaded files (PDF, images) and markdown text submitted for grading.
• Grading results -- the AI-generated grading output and score.
• Technical data -- server logs containing IP addresses and timestamps, retained for security purposes.

3. How we use your data

• To process and grade your submissions using AI language models.
• To allow you to retrieve your submissions and results.
• To allow teachers to manage exams and review submissions.
• To send you emails related to your account (verification, grading results).

4. Anonymous submissions

When an exam is configured as anonymous, the teacher cannot see which email address submitted a given file. Even if you are logged in, your identity is not disclosed to the exam owner. Your submission can still be retrieved by logging in with the same account.

5. Research dataset (opt-in only)

At the time of submission, you may explicitly consent to your submission being collected for research purposes. If you give this consent:

• Your submitted files (markdown, PDF, or images) may be included in a publicly released dataset aimed at improving AI grading and related research.
• If and when such a dataset is released, identifying fields (such as name, email, or student ID number) would be stripped before publication.
• This consent is optional and does not affect the grading of your submission.

6. Data storage and hosting

All data is stored on a European server hosted by Hetzner Online GmbH, in a data center located in Finland. Your data does not leave the European Union for storage purposes.

As much as possible, submissions are processed by AI services and models hosted at TU Wien (datalab servers in Austria). When load is high or that service is unavailable, we may instead use commercial LLM providers such as Mistral, Anthropic, OpenAI, and others. Some of these providers operate outside the European Union, in which case your submission may be processed outside the EU during grading. By accepting this privacy policy, you also accept the terms of service and privacy policy of whichever of these LLM providers is used to process your submission.

7. Data retention and deletion

• For non-anonymous submissions: you can view and delete your submissions by logging in with the corresponding email from your dashboard.
• Account data is retained until you request deletion.
• You may request complete deletion of your account and all associated data by contacting the Data Privacy Officer.

8. Your rights (GDPR)

Under the General Data Protection Regulation, you have the right to:

• Access the personal data we hold about you.
• Rectify inaccurate data.
• Request erasure of your data.
• Restrict or object to processing of your data.
• Data portability.
• Lodge a complaint with a supervisory authority.

To exercise any of these rights, contact: contact@nabla-grader.com

9. Legal basis for processing

• Contract performance -- processing submissions and delivering grading results.
• Legitimate interest -- platform security and abuse prevention.
• Consent -- optional research dataset inclusion.

10. Changes to this policy

We may update this policy. Changes will be posted on this page with an updated date.