The original title is: "TypeScript Branded Types vs. Nominal Types: Which Pattern Should You Use in 2026"

Short summary

TypeScript's branded types pattern uses phantom compile-time properties to add nominal typing behavior without runtime overhead, enabling type-safe distinctions between primitives like UserId and PostId. The technique leverages unique symbols or brand properties to prevent accidental type substitution at compile time while remaining completely invisible at runtime, providing zero performance cost. Teams can implement branded types through simple factory functions and generic utilities, making large-scale refactoring safer and code more maintainable than relying on structural typing alone.

• •Branded types use phantom properties to create nominal typing in TypeScript's structural system
• •Zero runtime overhead—brands compile away completely, leaving only plain strings
• •Prevents accidental type substitution between similar primitives like UserId and PostId

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