TypeScript Best Practices 2026

TypeScript continues to evolve, and with each release, we get new features that make our code more robust and maintainable. Here are my essential best practices for 2026.

1. Use strict Mode

Always enable strict mode in your tsconfig.json:

{
  "compilerOptions": {
    "strict": true
  }
}

2. Prefer Interfaces for Object Types

Use interfaces for object types and type aliases for unions, intersections, and primitives.

// Good
interface User {
  id: string;
  name: string;
  email: string;
}

// Good for unions
type Status = 'pending' | 'approved' | 'rejected';

3. Use Generic Constraints Wisely

Generics are powerful, but use them judiciously:

function getFirst<T extends { length: number }>(arr: T): T[0] | undefined {
  return arr[0];
}

4. Avoid any

Use unknown when you don’t know the type, and narrow it appropriately:

function processData(data: unknown): string {
  if (typeof data === 'string') {
    return data.toUpperCase();
  }
  throw new Error('Invalid data');
}

5. Use Template Literal Types

For type-safe string operations:

type EventName = `on${Capitalize<string>}`;

interface EventHandlers {
  onClick: () => void;
  onHover: () => void;
}

Conclusion

Following these practices will help you write more maintainable, type-safe TypeScript code. The key is to embrace the type system rather than fighting against it.