GraphQL vs REST — When to Use GraphQL and How to Build Your First API

Introduction

Learn GraphQL from scratch with practical examples. Covers schema definition, queries, mutations, subscriptions, and how to connect a GraphQL API to a React frontend.

Getting Started

This guide covers everything you need to know about GraphQL vs REST. Whether you're a beginner or experienced developer, you'll find practical examples and best practices here.

Key Concepts

• Core functionality — Understanding the fundamentals before diving into advanced features
• Practical examples — Real-world code you can use immediately in your projects
• Common pitfalls — Mistakes to avoid and how to debug when things go wrong
• Best practices — Industry-standard patterns for production-ready code

Quick Start

The fastest way to get up and running. Follow these steps to complete your first working implementation in minutes.

Advanced Usage

Once you've mastered the basics, these advanced patterns will help you handle edge cases and scale your implementation.

Troubleshooting

Common issues and how to fix them. When something breaks, start by checking these areas before diving deeper into the documentation.

Frequently Asked Questions

Is GraphQL better than REST?

It depends on your use case. GraphQL excels when you need flexible queries, have multiple client types (web/mobile), or want to reduce over-fetching. REST is simpler for CRUD operations, has better caching out of the box, and is more widely understood. Choose GraphQL for complex data requirements, REST for simple APIs.

What is a GraphQL schema?

A GraphQL schema defines the shape of your API — what queries clients can make, what types exist, and how data relates. It's written in GraphQL Schema Definition Language (SDL) and acts as a contract between client and server. Every GraphQL API must have a schema.

How do GraphQL resolvers work?

Resolvers are functions that execute when a field is queried. Each field in your schema has a resolver that fetches the actual data — from a database, another API, or any source. Resolvers receive four arguments: parent, args, context, and info.

What are GraphQL mutations?

Mutations are GraphQL operations that modify data (create, update, delete). Unlike queries, mutations execute serially to prevent race conditions. They follow the same syntax as queries but use the `mutation` keyword and return the modified data.

What are GraphQL subscriptions?

Subscriptions enable real-time data updates via WebSockets. Clients subscribe to events, and the server pushes updates when data changes. Use subscriptions for live chat, notifications, or any feature requiring real-time sync. Requires WebSocket support on both client and server.

How do I handle authentication in GraphQL?

Pass authentication tokens via HTTP headers (typically `Authorization: Bearer `). Extract the token in your server middleware and attach user info to the context object, which is passed to every resolver. Use context for authorization checks within resolvers.

Is GraphQL good for production?

Yes, many production systems use GraphQL at scale (GitHub, Shopify, Facebook). Key considerations: implement query depth limiting to prevent DoS attacks, use DataLoader for N+1 query problems, add proper caching layers, and monitor query performance.

What are common GraphQL mistakes?

Common mistakes: no query depth limiting (security risk), N+1 queries (performance killer), over-normalizing schemas, mixing concerns in resolvers, and ignoring caching. Follow best practices: use DataLoader, implement rate limiting, and keep resolvers focused on data fetching.