What’s the simplest way to add a basic frontend to my web API?

You may not need a framework at all. For a straightforward interface, regular HTML and CSS with a small amount of JavaScript and fetch() can call your API, parse the JSON, and update the page. Adding React or another large framework just to submit forms and display API responses can be unnecessary complexity.

Consider a server-rendered approach instead of a single-page application. HTMX with a templating system, or Alpine.js for small interactive pieces, lets you keep most of the application on the server while adding dynamic behavior where needed. This can be especially comfortable if you prefer backend development and want to minimize JavaScript.

Vue is a strong middle ground for backend-oriented developers. It’s approachable, but there are also officially supported choices for routing and state management when the application grows. React has a huge ecosystem, but its flexibility means you’ll have more decisions to make. Angular is capable and structured, though likely overkill for a small API-driven frontend.

Svelte is probably the best fit if you want a framework without a lot of ceremony. Its syntax stays close to HTML, CSS, and JavaScript, so you can get a basic application running quickly. Astro is also useful, but it may be more than you need unless you’re building a content-heavy site.

If you’re using PHP, Livewire is another option because it provides interactive components while keeping much of the work in the backend. You can build useful interfaces without learning a full JavaScript framework.