Userbase

Userbase is a backend-as-a-service specifically for static websites. It lets you add user authentication and a persistent database to a site built with just HTML, CSS, and JavaScript, without you having to write or manage any server-side code. You integrate it by adding their simple SDK to your project, and it handles everything from user sign-ups to data storage directly from the browser.

The tool works by handling all database operations and user authentication client-side. Its standout feature is built-in end-to-end encryption; all data is encrypted in the user's browser before it ever leaves their device, which is a major benefit for privacy and security. It is also completely open-source, meaning you can self-host the entire service to maintain full control, or use their hosted serverless option for convenience.

This is a perfect solution for front-end developers and indie makers who want to build full-stack applications—like personal note-taking apps, project management tools, or small SaaS products—without the complexity of building a backend. It radically simplifies the process of making a static site interactive and user-specific while handling tough security and compliance concerns like GDPR for you.