TypeScript Formatter: Keep Your Typed Code Clean and Consistent
Learn how to format TypeScript code for better readability. Explore type annotation formatting, interfaces, generics, and use our free online TS formatter.
February 4, 2026
Why Format TypeScript?
TypeScript has rapidly become the language of choice for large-scale JavaScript applications. By adding static types to JavaScript, it catches errors at compile time and makes code more self-documenting. However, TypeScript's additional syntax for types, interfaces, generics, and enums means there is even more code to keep organized. Consistent formatting is essential for maintaining the readability and maintainability that TypeScript is designed to provide.
Without formatting, TypeScript code can become particularly cluttered because type annotations add visual complexity that does not exist in plain JavaScript. A function with multiple typed parameters, a return type, and generic constraints can stretch across a very long line, making it difficult to read and review. A formatter manages this complexity by applying consistent line breaks and indentation.
TypeScript-Specific Formatting
Type Annotations
Type annotations are the most distinctive feature of TypeScript. Consistent formatting of annotations improves readability significantly. A colon should follow the variable or parameter name with a space before the type. For complex types, consider breaking them across multiple lines to maintain clarity.
Union types and intersection types benefit from formatting that places each type on its own line when the combined type is long. This makes it easy to see all possible types at a glance and to add or remove types without affecting other lines.
Interfaces and Type Aliases
Interfaces are a cornerstone of TypeScript development, defining the shapes of objects throughout your application. Well-formatted interfaces place each property on its own line with consistent indentation. Optional properties, readonly modifiers, and method signatures should all follow the same formatting pattern.
When interfaces extend other interfaces or when type aliases compose multiple types, proper formatting shows these relationships clearly. Each extended interface should be visible, and complex mapped or conditional types should be broken across lines for readability.
Generics
Generic types add another layer of complexity to TypeScript code. Well-formatted generics use consistent spacing around angle brackets and place constraints on their own lines when they become long. Functions with multiple generic parameters benefit from having each parameter on its own line, similar to regular parameters.
Generic utility types like Partial, Required, Pick, and Omit can nest deeply. A formatter ensures these nested generics are properly indented so you can trace the type transformation from outer to inner levels.
Consistency with JavaScript Formatting
TypeScript formatting should be consistent with JavaScript formatting conventions since TypeScript is a superset of JavaScript. All the same rules for indentation, semicolons, brace placement, and spacing apply. The additional TypeScript syntax should blend naturally with the JavaScript formatting rather than introducing a separate visual style.
This consistency is important because many projects contain both TypeScript and JavaScript files, and developers move between them frequently. When both languages follow the same formatting base, the transition is seamless.
How Our TypeScript Formatter Works
Our online TypeScript formatter applies industry-standard formatting to your TypeScript code instantly. Paste your code into the input field, and the tool handles everything from basic JavaScript formatting to TypeScript-specific syntax. It properly formats type annotations, interface definitions, generic types, enum declarations, and decorators.
The formatter parses your TypeScript code and reprints it with consistent indentation, proper line breaks, standardized spacing, and clean alignment. It handles all modern TypeScript features including template literal types, satisfies operator, and const type parameters.
Benefits for TypeScript Projects
- Type readability: Complex types are broken into readable structures that make the type system easier to understand and work with.
- Interface clarity: Well-formatted interfaces serve as clear documentation of your data shapes, making them valuable reference points for the entire team.
- Generic comprehension: Formatted generic types reveal their structure, making it easier to understand type transformations and constraints.
- Code review efficiency: When types and logic are consistently formatted, reviewers can focus on correctness rather than style.
Clean, consistently formatted TypeScript is the foundation of a maintainable, type-safe codebase. Use our free online TypeScript formatter to ensure your code meets professional standards.