Privacy Policy

Overview

blunder.ninja is a free, no-login chess openings practice tool. We believe in keeping things simple and transparent. This policy explains what data is collected and how it is used.

Data we collect

blunder.ninja itself collects no personal data. There are no user accounts, no sign-ups, and no server-side tracking.

Your practice progress and preferences (such as streak goals) are stored locally in your browser's sessionStorage or localStorage and never sent anywhere.

Advertising & cookies

This site displays advertisements served by Google AdSense. If you consent to cookies, Google may use cookies and similar technologies to serve personalised ads based on your visits to this and other websites.

Google's use of advertising cookies enables it and its partners to serve ads based on your browsing behaviour. You can opt out of personalised advertising by visiting Google Ads Settings or aboutads.info.

If you decline cookies or use an ad blocker, no advertising cookies are set. Ads may still be shown but will not be personalised.

For more information on how Google uses data, see How Google uses data when you use our partners' sites or apps.

Third-party services

• Google AdSense - advertising. Privacy policy
• Google Fonts - font delivery (Orbitron, Noto Sans). Fonts are loaded from Google's CDN; see Google Privacy Policy.
• jsDelivr / unpkg / cdnjs - open-source library delivery (chess engine, board UI). No personal data is collected by these CDNs beyond standard access logs.

Contact

Questions about this policy? Reach out via the Request Opening form on the site and mention it's a privacy query.