T3 StackvsT3 Turbo

T3 Stack and T3 Turbo share the same type-safe philosophy (tRPC, Prisma, NextAuth), but T3 Turbo wraps everything in a Turborepo monorepo and adds Expo for React Native mobile development. This isn't a quality comparison — T3 Turbo is built on T3 — it's a scope comparison about whether you need mobile and monorepo capabilities.

T3 Turbo's monorepo structure organizes code into packages: `@acme/api` (tRPC routers), `@acme/db` (Prisma schema and client), `@acme/auth` (NextAuth configuration), `@acme/ui` (shared components). Both the Next.js web app and the Expo mobile app import from these shared packages. This means your API types, database models, and auth logic are written once and shared across platforms — changes propagate automatically.

The trade-off is complexity. T3 Stack is a single Next.js application that's simpler to understand, deploy, and debug. T3 Turbo adds Turborepo configuration, workspace management, and Expo setup — even if you don't build a mobile app immediately. For developers who know they'll eventually need a mobile app, starting with T3 Turbo prevents the painful migration from a single app to a monorepo later.

Choose T3 Stack if you're building a web-only product and want the simplest possible setup with tRPC type safety. Choose T3 Turbo if you plan to build both a web app and a mobile app sharing the same backend, or if you prefer monorepo architecture for code organization.