Privacy policy

Last updated: November 12, 2026. This policy covers chess123.app and Chess Vision (see.chess123.app), run by DS Net Labs, Coimbatore, India ("we"). Contact: achessapp36@gmail.com.

The short version

You can use Chess Vision without an account. Your progress then stays in your own browser and is never sent to us. If you subscribe, we keep your email address, your progress and your subscription status so they work on every device. Ads (for non-subscribers) and anonymous usage statistics are described below.

What stays in your browser

Chess Vision saves your progress and settings in your browser's local storage (levels, results, review queue, language, display settings). This is needed for the site to work and is not sent to us. Clearing your browser data deletes it; the "Back up progress" link lets you keep a copy as a code or file.

Accounts and subscriptions

• Account: if you sign in, we store your email address and a login record with Supabase, our database provider. Signing in with Google gives us your email address and name from Google.
• Progress sync: for subscribers we store a copy of your progress linked to your account.
• Payments: payments are handled by Dodo Payments, which acts as the merchant of record. We never see your card details. We receive your subscription status, plan, renewal date and a customer reference.

Advertising

Non-subscribers see ads. Outside Russia ads come from Google AdSense; in Russia from the Yandex Advertising Network. These providers may use cookies or similar technology to show and measure ads. In the European Economic Area, the UK and Switzerland, Google asks for your consent first; you can change your choice at any time with the "Privacy and cookie settings" link in the site footer. See how Google uses data in advertising. Subscribers see no ads and no ad scripts are loaded for them.

Usage statistics

To tune difficulty we record anonymous events with PostHog (EU servers): for each round, the position, level, mode, result and time taken, and the site language. PostHog runs without cookies or browser storage on our site; we do not link these events to your name or email address.

Hosting

The sites are served by Cloudflare, which processes your IP address and request data to deliver pages and protect against abuse.

How long we keep data

Account, progress and subscription data are kept while your account exists. Payment records are kept as long as tax law requires. Usage statistics are kept for up to 12 months.

Your rights

You can ask for a copy of your data, a correction, or deletion of your account and its data by writing to achessapp36@gmail.com. Depending on where you live you may have further rights, including the right to complain to a data protection authority.

Children

The sites are not directed at children under 13, and we do not knowingly collect account data from them.

Changes

If this policy changes we will update the date above; material changes will be shown on the site.