REST API Basics & Best Practices Explained

RESTful APIs let different parts of a system talk to each other using standard HTTP methods. They’re the most common way developers build and consume APIs today, powering everything from mobile apps to backend microservices.

In this article, you’ll learn how to design clean, consistent REST APIs by following proven best practices, so you avoid the messy, inconsistent patterns that make APIs hard to use and maintain.

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1. Resource Modeling: The Foundation of REST

In REST, everything is a resource — a product, a user, a review. These resources are exposed through URLs using nouns, not verbs:

• ✅ GET /products

• ❌ GET /getAllProducts

Resources can be individual items or collections:

• Collection: /api/v1/products

• Single item: /api/v1/products/123

• Nested resource: /api/v1/products/123/reviews

Clear, consistent URL design makes your API predictable, which is a big plus for developers using it.

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2. Filtering, Sorting & Pagination

Real-world APIs return large datasets. To avoid overwhelming the client (and your servers), we need to support filtering, sorting and pagination.

Filtering

Let clients narrow down the result set:
GET /products?category=books&inStock=true

Sorting

Let clients control the order:
GET /products?sort=price_asc
GET /products?sort=rating_desc

Pagination

Split large datasets into pages:
GET /products?page=2&limit=20

Pagination is typically managed with page and limit query parameters. But there are other styles as well:

• Offset-based: ?offset=40&limit=20

• Cursor-based: ?after=xyz123

These tools improve performance, reduce bandwidth, and give frontend teams (and other services) more control.

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3. HTTP Methods: Map to CRUD

REST uses standard HTTP methods for basic operations:

Example:

• GET /products/123 — fetch a product

• POST /products — create a new one

• PATCH /products/123 — update its price

• DELETE /products/123 — remove it

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4. Status Codes & Error Handling

Your API should speak the language of the web, which means it should also return the proper HTTP status codes.

Common codes

• 200 OK — success

• 201 Created — resource created

• 204 No Content — success, nothing to return

• 400 Bad Request — invalid input

• 401 Unauthorized — user not authenticated

• 404 Not Found — resource doesn’t exist

• 500 Internal Server Error — something broke

Standard error responses

{
  "error": {
    "code": "VALIDATION_ERROR",
    "message": "Invalid product ID format",
    "details": [...]
  }
}

Keep it consistent. The client should never be guessing what went wrong.

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5. RESTful API Design Best Practices

Here’s a checklist to level up your API design:

• ✅ Use plural nouns for resource names (/products)

• ✅ Keep URLs consistent and hierarchical

• ✅ Support filtering, sorting, and pagination

• ✅ Use content negotiation when needed (Accept: application/json)

• ✅ Version your APIs (/v1/users)

• ✅ Include HATEOAS links for discoverability (optional but useful)

Bad API design leads to confusion, inconsistent implementations, and long-term pain. Good design saves time and scales with your product.

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Want to build real RESTful APIs and master system design?

Here are two ways I can help you with that:

• Apply to join my mentorship here

• Prefer a self-paced start? Grab my System Design course here

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Recap

We covered the core building blocks of great RESTful APIs:

• Resource modeling and clean URL design

• Filtering, sorting, and pagination techniques

• Proper use of HTTP methods

• Meaningful status codes and consistent error responses

• Best practices for scalable, intuitive APIs