The safest place for your data is a server we never built. Here is exactly how this site is engineered, so you can verify rather than trust.
Invoices, customers, prices, your logo — all of it is stored in your browser's local storage on your own phone or computer. There is no database of customer data to breach, because none exists. You can confirm this yourself: open your browser's developer tools and watch the network tab while you work.
Checkout happens on Stripe's own servers (you'll see the address change to stripe.com). Stripe is a PCI DSS Level 1 certified payment processor — the highest level — and processes payments for millions of businesses. Your card number never touches our infrastructure, and we couldn't see it if we wanted to.
Found a vulnerability? We publish a standard security.txt. Report it via Support — reports are read within one business day and we'll credit you in the changelog if you'd like.