Privacy policy

Last updated: 31 August 2026

The short version

531 can be used without an account, with training data stored locally on your device. Premium accounts can also store a synced training backup with Supabase.

Training data

Your training maxes, programme settings, workout history, completed sets, and accessories are stored locally so the app can work offline. When Premium cloud sync is enabled, a copy of this training data is stored in Supabase and associated with your account so it can be restored on another device.

Optional accounts

If you create an account, Supabase processes your email address, user ID, authentication session, account-related Premium entitlement status, and—when you use Premium cloud sync—your training backup.

Purchases

Stripe processes Founder Lifetime purchases made on this website. RevenueCat and the applicable app store process in-app purchases and subscriptions. We store the purchase reference, email address, and entitlement information needed to provide Premium access and handle refunds.

Website analytics

With your consent, this website uses Google Analytics cookies to understand site usage and improve the website. You can accept or reject analytics cookies in the cookie banner, and change your choice at any time using Cookie settings in the website footer.

Your choices

You can export or reset local data from Settings. Signed-in users can initiate permanent account deletion from Settings; this deletes account data and the associated server backup. Account deletion does not automatically cancel an app-store subscription.

Contact

For privacy questions, use our contact form. We process the details you provide solely to respond to your enquiry.