Privacy Policy

Last updated: March 2026
What We Collect

When you use Deckbuilder, we collect anonymous usage data to improve the service and for research purposes. This includes: a randomly generated session ID (not tied to any personal information), device type, browser name and version, operating system, screen resolution, timezone, and language preferences. We also collect behavioral data such as pages viewed, features used, and errors encountered. All data collection requires your explicit consent via the cookie banner.

What We Do NOT Collect

We never collect your name, email address, or any personally identifiable information. IP addresses are stored only as a one-way SHA-256 hash — the original IP cannot be recovered. We do not sell, share, or transfer your data to third parties.

Card Data

Uploaded CSV files are processed in memory on our server. Card names are matched against a local copy of the Scryfall card database — no data is sent to Scryfall per upload. You should not upload files containing personal information.

AI Deck Building

When you request a deck to be built, your card pool is sent to the OpenAI API to generate the deck list and strategy. This data is subject to OpenAI's data usage policies. We do not send any personal information — only card names, quantities, and card metadata.

Data Retention

Analytics event data is retained for 24 months. Card collection and deck data is retained for 12 months from the date of upload. You may request deletion of your data by contacting us.

Cookies

We use a single session cookie (session_id) containing a randomly generated UUID. This is required for the app to function and does not track you across other websites. Analytics tracking is only enabled if you choose "Accept All" in the cookie consent banner.

Your Rights

You can withdraw consent at any time by clicking "Cookie Settings" in the footer. You may request access to or deletion of any data associated with your session ID by contacting us.