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When you're building a website, there's more to think about than design and basic functionality. You also need to consider how search engines and crawlers interact with it, too. In this guide, @imsaartwito helps you find and fix common technical SEO issues on your site.

The Model Context Protocol lets your AI agents talk to external tools. And while this is super helpful, it comes with some pretty serious security risks, too. In this course, you'll learn about the biggest risks, building MCP security programs, compliance frameworks, and more.

A vector database stores data as lists of numbers called embeddings, which lets it search by meaning. And it's what powers many recommendation systems, RAG apps, and AI agents. In this course, you'll learn how they work, from the math to a working semantic search project.

If you're trying to use Claude Code in a Flutter project, it'll work better with clear structure and rules. And here, Jesutoni shares some best practices for building Flutter apps faster with Claude. You'll set up CLAUDE.md, feature-first folders, reusable skills, subagents, hooks, and a helpful sprint workflow.

RT @Talenmud: If you told me 3 years ago I'd be the youngest one in the room at an open source conference in a different continent I wouldn't believe you. Here I am at ATO for MLH. Met @ossia whose platform taught me to code. @SwiftAlphaOne called it a tech renaissance. Younger me losing it.

If you have a website, big or small, it might become a target for attackers. So you should be familiar with the top ways they might try to exploit vulnerabilities. In this article, @manishmshiva talks about SQL injection, cross-site scripting, weak authentication, and more, plus how to fix the issues.

If you're a freelance dev, you might often work with design studios to create client apps. But how do you make sure you're all on the same page and collaborate effectively? In this guide, @reetain_raina shares tips about understanding the project, clarifying your role, defining ownership, and more.

Ok let's keep going with the cool historical facts. On this day in 1971(!), the first email EVER was sent. It introduced the username@domain format we use to this day. So for today's coding challenge, you'll build a little email sorter. Go check out the rules and try to solve it on the freeCodeCamp mobile app.

25 years ago, Google launched image search. And for today's coding challenge, you'll imitate it. Check it out on the freeCodeCamp mobile app.

AI agents are more useful when they can remember, use tools, and run from secure places. In this course, Shawn teaches you how to build a Telegram AI agent with Vercel, Cursor, and Composio. You'll add app integrations, long-term memory, mobile access, and scheduled tasks with Vercel Cron along the way.

Healthcare data is sensitive, so sending it to a cloud AI service isn't always an option. In this tutorial, Lakshmi shows you how to build a local healthcare AI assistant with MedGemma, Ollama, and Open WebUI. You'll run the model on your own machine, chat with a medically tuned LLM, upload medical images, and more.

Computers can perform calculations incredibly fast. But decimals can still trip them up. In this video essay, @ania_kubow explains why floating-point math can break money calculations. You'll learn why values like 0.1 and 0.2 are hard to store exactly, how rounding errors add up, and why financial systems use integers for currency.

If your React apps feel like they're missing a layer of safety and clarity, this course is for you. In it, Rachel shows you how to refactor a project to be fully type-safe, more readable, and easier to maintain. You'll define component props, handle function props, and catch bugs before they reach the browser, too.

Training larger AI models often means spreading the work across multiple GPUs. In this course, Kian explains Distributed Data Parallelism from the ground up. You'll learn about model parallelism, manual batch averaging, All Reduce, DDP hooks, plus the performance tradeoffs, too.

Local LLMs can answer prompts, but they can't reach the outside world on their own. In this tutorial, Darsh shows how to build a local AI agent with tool calling and memory. You'll use Python, LangChain, and other tools so the agent can call functions, handle follow-up questions, and run on your own machine.

Generative AI systems can create content, like text or code, based on data they've been trained on. And in this bootcamp, @andrewbrown (and many other instructors) teach you key GenAI concepts. You'll get hands-on experience with Python data libraries, learn about prompt engineering, model fine-tuning, and AI agents, and lots more.

AI products can look simple from the outside: a user prompt goes in, and an answer comes back. But production AI features need much more than a model API call. In this article, Olamilekan explains the engineering behind reliable AI products: permissions, guardrails, evals, observability, human review, and more.

Most commercial voice assistants send your voice data to cloud servers before they respond. But if you build your own assistant with open source tools, you can run everything right on your phone. This gives you more privacy and control & Surya shows you how it works here.

Many fraud detection systems evaluate events in isolation. But this approach has a problem: sophisticated attacks rarely trigger individual threasholds. In this guide, Kamal explains how graph databases help, and teaches you about precomputing derived edges, writing parameterized Cypher queries, and more.

You may have learned a lot of algorithms in your programming journey, but have you thought about why they work the way they do? Well, that's what you'll learn in this course. It goes into the mathematical reasoning behind an algorithm's performance and covers Divide and Conquer, probabalistic analysis, heaps, hash tables, and lots more.

The Model Context Protocol helps connect LLMs to external tools, databases, and APIs. But letting your AI agents take real-world actions can introduce a lot of security risks. In this course, you'll learn about common agent exploits and how to defend against them.

WOAH. On this day in 1994 (so, like a bajillion years ago at this point, right?), Netscape Navigator was released. And today's coding challenge celebrates that with a fun little exercise. Check it out on the freeCodeCamp mobile app.

For today's coding challenge, you'll build a little word counter. Easy peasy lemon squeezy...right? Go and see on the freeCodeCamp mobile app.

The field of Cryptography is all about securing both data and communication between systems. And in this course, you'll learn the basics like hashing, symmetric and asymmetric encryption, and more. By the end, you'll have built a fully-functioning Python-based command line cryptography tool.

Google just released its most sophisticated reasoning model yet: Gemini 4 Argon. And if you want to get it up and running quickly, this crash course is for you. In it, @beaucarnes and @ania_kubow teach you about configurable thinking levels, multi-turn state, async background execution, and more.

Cloud-based LLMs are super powerful. But sometimes local models are a better choice, especially when you're dealing with sensitive info. Here, Manoj shows you how to use Ollama, Python, and LangChain to run LLMs locally and build privacy-first, AI-powered apps.

Autoregressive token generation is notoriously slow and memory-intensive (and I mean with a name like that...!). And if you just need your model to make structural or routing decisions, it's overkill. In this Jev course, you'll learn how to build super fast, decision-oriented architectures that process inputs all within the initial prefill stage.

NVIDIA’s Certified Associate AI Infrastructure and Operations (NCA-AIIO) is an entry level certification. It tests your ability to run and manage AI systems. Here, you'll learn everything you need to pass the exam, including GPU architecture, ML, and more.

If you want to defend against attackers, you have to understand how they attack. And you can learn how to break into systems (ethically and responsibly) in this course. You'll learn about target reconnaissance, vulnerability assessment, web exploitation, and more using a dedicated Capture the Flag machine.

If you want to improve your technical writing skills, this course is for you. It'll help you make your writing more concrete and practical while teaching you to communicate clearly. You'll learn about framing definitions, describing objects and processes, writing formal reports, and more.

Dark mode toggles usually rely on JavaScript, but they don't have to. In this tutorial, @jcubic explains how to build one with just HTML and CSS. You'll use radio buttons, labels, CSS variables, and more to switch themes while keeping the site usable without JS.

When you're building a website, you'll want it to be responsive, fast, and efficient. And there are many ways you can optimize the performance of your websites. In this handbook, @TanGuangzh54866 teaches you about server-side rendering, using a CDN, caching, file compression, image optimization, and more.

Calculus is a powerful tool for understanding change, motion, and growth - and it's good to know as a dev. In this College Calculus course, Ed teaches you the key concepts through the lens of Python. You'll learn about limits, derivative rules, slope interpretation, various theorems, and how to apply symbolic math libraries like SymPy for graphing & computation.

An Intrusion Detection System acts like a security camera for your network. And in this in-depth tutorial, @chairahalkar teaches you how to build a real-time IDS with Python. It'll alert you to any potential cyber attacks and security breaches so you can keep your network safe.

If you want to learn how to build and deploy ML models, this course is for you. It covers Exploratory Data Analysis, Feature Engineering, Model Validation, & MLOps integration. By the end you'll be able to manage complex data projects & deploy your models.

If you get a context-related Flutter error, it's easy to just look up an answer on Stack Overflow. But if you don't really understand the three trees Flutter is built on, and what BuildContext is, you'll just keep googling. Here, @GiduduNicowalte gives you the guide he wishes he'd had to help you truly comprehend these errors.

For today's coding challenge, you'll get a positive integer and you'll need to return a string with all the integers from 1 up to (and including) your integer. In numerical order. So like if you're given 5, you'll need to return "12345". Check it out on the freeCodeCamp mobile app.

Back to history! On this day in 1988 the first major internet worm slithered into existence. It infected almost 10% of computers connected to the net after only 1 day. For today's challenge, you'll have to figure out how many computers were affected after a certain number of days. Check it out on the freeCodeCamp mobile app.

Moving an LLM from prototype to production can introduce many security, privacy, and reliability issues. So Chidiebere is here to help you learn about and build a solid AI guardrail system. You'll build defensive layers with Python, prevent prompt injection, manage data access, and more.

Open source isn't just about the code. It's a community of contributors and maintainers coming together to build software. In this handbook, @AbdulTa62185243 goes over practical steps to help you find projects, make meaningful contributions, and grow your career.

Your notes, PDFs, and docs are hard to search once they pile up in folders. In this tutorial, Darsh teaches you how to build a private RAG Q&A agent that runs on your own machine. You'll use Python, LangChain v1, Ollama, Qwen, and ChromaDB to query your documents and get answers with cited sources.

Lots of web apps use badges for notifications, status labels, and so on. But a boring old static badge isn't enough these days. So adding some fun animations can really help. In this tutorial, @gupta05_vaibhav teaches you how to build an animated “success” badge using shadcn/ui, Tailwind CSS, and Framer Motion.

Running LLMs locally has a lot of advantages. Like, it gives you access to AI capabilities offline and ensures data privacy, all without cloud costs. In this in-depth tutorial, @KraneOliver shows you how to set up, use, and customize popular models locally with Ollama.