TypeScript Formatting: Keep Your Types as Clean as Your Logic

TypeScript adds a layer of complexity to JavaScript formatting — type annotations, interfaces, generics, and enums all need consistent styling. When type definitions span multiple lines, proper formatting becomes crucial for readability and maintainability.

What Is TypeScript Formatter?

TypeScript formatting applies rules for interface declarations, type annotations, generic constraints, and enum formatting in addition to standard JavaScript rules. Our TypeScript Formatter handles all TS-specific syntax.

How to Use TypeScript Formatter on DevToolHub

1. Open the TypeScript Formatter tool on DevToolHub — no signup required.
2. Paste or enter your input data in the left panel.
3. See the result instantly in the output panel.
4. Copy the result or download it as a file.

Formatting TypeScript Interfaces

Clean type definitions improve API comprehension:

// Before
interface UserResponse{id:number;name:string;email:string;roles:Array<{id:number;name:string;permissions:string[]}>;metadata:{lastLogin:Date;loginCount:number};}

// After
interface UserResponse {
  id: number;
  name: string;
  email: string;
  roles: Array<{
    id: number;
    name: string;
    permissions: string[];
  }>;
  metadata: {
    lastLogin: Date;
    loginCount: number;
  };
}

Pro Tips

• Use interface for object shapes and type for unions, intersections, and computed types
• One property per line in interfaces — complex nested types need clear visual hierarchy
• Put generic constraints on the same line if short: , new line if long
• Enable strict mode in tsconfig for maximum type safety benefits

When You Need This

• Formatting TypeScript interfaces before code review
• Standardizing type definitions across a monorepo
• Preparing TypeScript examples for API documentation
• Cleaning up auto-generated types from GraphQL or OpenAPI codegen