What Is This Course?

TypeScript: Basics to Advanced is a free course that teaches TypeScript step by step, the way companies use it.

It is made for developers who already know JavaScript. You start with your first type and finish by building a complete REST API with Node.js, Express and MongoDB.

• 33 sessions, each one a single page on GitHub
• 1 to 2 hours per session, including practice
• Completely free: no signup, no paywall, no videos to sit through

Is This Course for You?

This course is for you if:

• You know JavaScript and want to learn TypeScript
• Your team uses TypeScript and you want to understand it properly
• You build backends or full-stack apps with Node.js
• You are preparing for a TypeScript or Node.js interview

What you need before you start

• Basic JavaScript: variables, functions, arrays, objects, classes and promises
• Node.js 24 or newer
• A code editor, such as VS Code

You do not need any TypeScript experience. If JavaScript is also new to you, start with the free JavaScript course first.

What Is TypeScript?

TypeScript is JavaScript with types. You describe what your data should look like, and TypeScript checks your code before it runs.

Here is a small example from Session 09. An order can have only four statuses, and someone makes a typo:

type OrderStatus = "pending" | "paid" | "shipped" | "cancelled";

interface Order {
  readonly id: number;
  status: OrderStatus;
}

const order: Order = { id: 1001, status: "pending" };
order.status = "shiped";

TypeScript catches the mistake before the code ever runs, and even suggests the fix:

error TS2820: Type '"shiped"' is not assignable to type 'OrderStatus'. Did you mean '"shipped"'?

In plain JavaScript, the wrong status would be saved without any warning, and someone would find the bug much later. TypeScript is built to catch mistakes like this early.

What You Will Learn

The course has 7 parts. Each part builds on the one before it.

See the full list of all 33 sessions

What Makes It Different

• Up to date. Most tutorials online use TypeScript 5. This course uses the newest version, TypeScript 7, and tells you whenever an older tutorial shows something different.
• Every example is tested. All the code was run. Every output and every error message in the course is real, so you can compare it with yours.
• Easy to picture. 362 animated diagrams show what happens inside your code.
• Learn from mistakes. Every session shows common beginner mistakes, with the real error and the fix.
• Backend focused. No browser code. The examples come from real servers: users, orders, carts, logins and APIs.
• One step at a time. A session only uses what earlier sessions have already taught.

What Every Session Contains

Across the course, that adds up to 352 beginner mistakes, 261 practice exercises and 406 interview questions.

The Final Project

In the last session you build a complete Task Management API in TypeScript, using everything from the course:

• Users register and log in (JWT tokens and hashed passwords)
• Each user adds, updates and deletes their own tasks
• Tasks can be filtered by status and loaded page by page
• Admins can see all users
• 25 automated tests check that everything works

How to Start

Step 1: Check that Node.js is installed. Open a terminal and run:

node -v

You need version 24 or newer. If you don't have it, install the LTS version from nodejs.org.

Step 2: Create a practice folder. Make a folder called ts-practice and open it in VS Code (File > Open Folder).

Step 3: Open Session 01. Read it and do the "Try It Yourself" part. Session 02 then installs TypeScript with you, step by step.

Tips to get the most out of it

1. Go in order. Every session builds on the ones before it.
2. Type the code yourself. Don't copy and paste. Typing helps you learn.
3. Check and run. Run npx tsc to check your code and node to run it, then compare with the session.
4. Do the exercises before you move on to the next session.

At one session a day, most learners finish in 6 to 7 weeks.

A Free Learning Path

This course is one of three free courses that work together:

All three use the same simple style and the same kind of examples, so moving from one to the next is easy.

FAQ

Is it really free?
Yes. No signup, no paywall, no email list.

Are there videos?
No. Everything is written, with animated diagrams for the hard parts, so you can learn at your own pace.

I have never used TypeScript. Can I follow it?
Yes. Session 01 starts from zero. You only need basic JavaScript.

My company uses an older version of TypeScript. Is this still useful?
Yes. The language is the same, and the course points out the places where older versions behave differently.

I found a mistake. What should I do?
Please open an issue on GitHub. Every report helps the next learner.

Thanks for Reading

If this course helps you, please give it a star on GitHub. It helps other developers find it. And if you know someone who wants to learn TypeScript, share it with them.

Are you learning TypeScript right now? Tell me in the comments what you find hardest.

Start with Session 01: Introduction to TypeScript

Author: Mohin Sheikh. Follow me on GitHub for more free courses.