Privacy policy

Last updated 18 October 2026. StackSiren (formerly StackCheck) is operated by StackBySolo.

What we collect

Scans: the URL you enter, your email and your IP address (for rate limiting and abuse prevention). We fetch only public content and don't store page content. Anonymous summaries (domain, score, issue count, referral source) may appear in server logs.
Email: we need your email to deliver your score and link it to your report, purchases and account. We only add it to our mailing list in Kit (ConvertKit) if you tick the optional newsletter box on the scan form; it is then tagged with how you found us (for example from StackBySolo). Unsubscribe any time via the link in any email.
Payments and accounts: processed by Stripe, which receives your payment details and email under its own privacy policy. We don't see your card details. Your credit balance, plan, monitored app URLs, referral source and short weekly rescan summaries are stored with Stripe as customer, checkout and subscription data.
Analytics: Vercel Web Analytics (cookieless, aggregated).

sc_acct: strictly necessary, httpOnly; keeps you signed in to your account on this device.
sc_ref: httpOnly, 90 days; records the site or campaign that referred you (for example a StackBySolo link) so we can attribute signups and sales. It contains no personal data.

On Solo and Builder plans we passively rescan the apps you choose once a week until you remove them or cancel.

You can ask us to access or delete your data. Manage or cancel plans through the Stripe customer portal linked from your account.