Inertia vs separate API and SPA, which is better?

Inertia is better when you have one frontend (web only), one team, and you want development velocity. A separate API and SPA is better when you have multiple frontends (web plus mobile plus partner integrations), separate frontend and backend teams that need independent release cadences, or your backend is consumed by third parties. For most internal SaaS web apps and customer portals, Inertia ships faster and stays simpler to maintain. For public APIs or omnichannel commerce, separate is the right call. More on our API development page.