Here's a question you'll inevitably face as a dev: which programming language (or library/tool) should I learn/use? This can be frustrating - but here, Ryan gives you a framework for evaluating this choice. He teaches you about the Law of Suitability and how it can help you

Clustering is a key technique in unsupervised machine learning that helps you discover valuable insights in your data. And in this handbook, @tatevkaren7 explains how it works in Python. She covers K-means clustering, Hierarchical clustering, and DBSCAN clustering, along with

I'm thrilled to announce this year's freeCodeCamp's Top Open Source Contributors. It's 🦃 Thanksgiving 🥧 and I'm thankful for all 611 of you! 2025 has been a super productive year for the global freeCodeCamp community. As we start our 12th year as a community, we’re firing on

Keeping documentation up to date can be a time-consuming and frustrating manual process. But an approach called Documentation as Code helps streamline things with automation, versioning, and more. In this guide, @ezinne_anne explains how to set up docs as code with Docusaurus

For today's coding challenge, you'll calculate someone's current age. And if you're a Blink182 fan, now you have that classic song stuck in your head...🎶 Anyway, go try out the challenge on the freeCodeCamp mobile app.

CSS Flexbox helps you build user interfaces that can adapt to any screen size. And in this course, you'll learn how to use it in your projects. It covers reordering elements, what flex-grow, flex-shrink, and flex-basis are really doing, how to align items properly, and ends

Apps that handle user accounts need a secure way to tell who's who. This is what authentication is for - it tells you the person trying to access the app is who they say they are. In this article, @thejoanayebola teaches you how to build a secure authentication system with JWT

Closures are one of the most misunderstood parts of JavaScript - but they're important to understand. So @sumit_analyzen wrote this in-depth handbook to teach you the detailed ins and outs of closures. You'll learn about functions and parameters, accessing variables, scope, let

freeCodeCamp can create and share so many high-quality, free resources because of our amazing volunteer community. These kind people, from all over the world, contribute in so many ways to our mission - and we couldn't be more grateful. So here's this year's Top Contributors.

If you work with data, a comprehensive analytics dashboard can be really helpful. And in this guide, Stefan walks you through setting one up using Next.js and some popular charting tools. You'll set up the dashboard, configure the charts, and gain some insights into analyzing

Today's coding challenge follows nicely from yesterday's (that was FizzBuzz. This is BuzzFizz!). You'll check if a FizzBuzz sequence is correct. Go check it out on freeCodeCamp's mobile app.

As a developer, you'll want to have a portfolio where you can showcase your work and skills. Bonus points if you build it yourself from scratch - which is what @sprucekhalifa teaches you how to do here. You'll use just HTML and CSS and build out header, hero, about, work, &

You may have heard of "vibe coding" - it's when you give instructions to the LLM and let it do the heavy lifting. So how well does this work? And is it good enough for production code? In this article, @TheAnkurTyagi discusses how AI-assisted coding works, why code reviews are

CockroachDB may have a funny name, but the creators had a point: this database is tough, like a cockroach. And in this book, @POnukwili walks you through its features and how to use it. He also helps you deploy your own Cockroach DB instance on Kubernetes, automate backups,

When you're coding in React, it's easy to overuse useState - and this can make things overly complex. So in this tutorial, @_jongbo teaches you how and when to use derived state to simplify your components. You'll learn how to derive state from existing data, how to prevent

When you're learning back-end development, you'll need to learn to think like a back-end dev. And that's what @tech_girlll teaches you how to do in this tutorial. Along the way, you'll learn how to use the Django REST framework to build back-end APIs while separating concerns,

Today's coding challenge is the popular FizzBuzz coding problem. Find it and see if you can solve it on the freeCodeCamp mobile app.

Managing your Python projects can get complicated, especially as they grow. So in this guide, @manishmshiva shows you how to use a helpful open source tool called Poetry. He shows you how to set it up, how its pyproject.toml file works and what it does, and compares Poetry to

Computers can understand and produce human-like speech thanks to Natural Language Processing. And in this handbook, Oleh shows you how to use NLP techniques and tools in your own projects. You'll learn about typical NLP tasks, key machine learning methods, how to prepare and

On this episode of the freeCodeCamp podcast, Quincy interviews university students Cindy Cui and Alison Co. They discuss when NOT to use AI in your hackathon projects (they just won the NW Hacks hackathon, btw), how to secure good internships, and more. You can watch the