TypeScript Best Practices for 2025
TypeScript has become an essential tool for modern web development. Here are some best practices to help you write better TypeScript code.
Use Strict Mode#
Always enable strict mode in your tsconfig.json:
{
"compilerOptions": {
"strict": true,
"noImplicitAny": true,
"strictNullChecks": true
}
}This catches potential errors at compile time rather than runtime.
Prefer Interfaces Over Type Aliases for Objects#
When defining object shapes, prefer interfaces:
// Good
interface User {
id: number;
name: string;
email: string;
}
// Less ideal for objects
type User = {
id: number;
name: string;
email: string;
}Interfaces can be extended and merged, making them more flexible for object definitions.
Use Utility Types#
TypeScript provides powerful utility types that can save you time:
interface Todo {
title: string;
description: string;
completed: boolean;
}
// Make all properties optional
type PartialTodo = Partial<Todo>;
// Make all properties required
type RequiredTodo = Required<Todo>;
// Pick specific properties
type TodoPreview = Pick<Todo, 'title' | 'completed'>;
// Omit specific properties
type TodoInfo = Omit<Todo, 'completed'>;Avoid Using any#
The any type defeats the purpose of TypeScript. Instead, use unknown when the type is truly unknown:
// Bad
function processValue(value: any) {
return value.toString();
}
// Good
function processValue(value: unknown) {
if (typeof value === 'string' || typeof value === 'number') {
return value.toString();
}
throw new Error('Invalid value type');
}Conclusion#
Following these best practices will help you leverage TypeScript’s full potential and write more robust applications.