Mobile applications often need to communicate important information to users, even when the app isn't actively running. Local notifications are an excellent way to achieve this, allowing you to display messages, reminders, or alerts directly on the u...  ( 19 min )

On this week's episode of the podcast, freeCodeCamp founder Quincy Larson interviews Tai Groot. He's a back end software engineer and maintains an open source project used by companies like Google. For the first half of the interview we talk about ba...  ( 4 min )

Blob, Blob, Blob. What's the most effective way to create blob shapes in CSS? Turns out, as always, there are many. Let's compare them together! CSS Blob Recipes originally published on CSS-Tricks, which is part of the DigitalOcean family. You should get the newsletter.  ( 13 min )

Modern mobile applications are far from static, single-view experiences. Instead, they are dynamic, multi-faceted environments where users seamlessly transition between different features, content, and functionalities. Because of this inherent comple...  ( 11 min )

Transformers have changed the game in machine learning. From powering chatbots and search engines to enabling machine translation and image generation, they're at the core of today’s most impressive AI models. But the field moves fast. New techniques...  ( 4 min )

Red Hat Enterprise Linux (RHEL) is a leading enterprise-grade Linux distribution widely regarded as the gold standard for mission-critical server environments. It provides robust, secure, and scalable solutions for organizations ranging from small bu...  ( 14 min )

KelpUI is new library that Chris Ferdinandi is developing, designed to leverage newer CSS features and Web Components. I've enjoyed following Chris as he's published an ongoing series of articles detailing his thought process behind the library, getting deep into his approach. You really get a clear picture of his strategy and I love it. KelpUI originally published on CSS-Tricks, which is part of the DigitalOcean family. You should get the newsletter.  ( 7 min )

Web development combines multiple technologies to create interactive applications that run in web servers and browsers. Modern web apps require understanding both the server-side (back end) and client-side (front end) and how they communicate with ea...  ( 5 min )

If you’re an indie hacker – that is, someone building your own side project, startup, or digital product solo or with a small team – you know that hosting matters. You’re juggling product development, community-building, marketing, support, and ever...  ( 7 min )

MCP (Model Context Protocol) lets you connect your code, data, and tools to AI applications like Claude and Cursor. This handbook explains how it works with real-world analogies, and shows you how to build a custom MCP server using TypeScript that fe...  ( 27 min )

The CSS if() function enables us to use values conditionally, which we can already do with queries and other functions, so I’m sure you’re wondering: What exactly does if() do? Let's look at a possible real-world use case. Poking at the CSS if() Function a Little More: Conditional Color Theming originally published on CSS-Tricks, which is part of the DigitalOcean family. You should get the newsletter.  ( 10 min )

As online scams become more sophisticated, Carrie Webster explores whether good UX can serve as a frontline defense, particularly for non-tech-savvy older users navigating today’s digital world.  ( 16 min )

With the rise of AI tools over the past couple years, most of us are learning how to use them in our projects. And in this article, I’ll teach you how to build a quick Discord bot with LangGraph and Composio. You’ll use LangGraph nodes to build a bra...  ( 20 min )

I’ve never been the loudest person in the room. In fact, the first time I submitted a conference talk, I hovered over the submit button for nearly an hour. I was convinced someone else had more experience, a better résumé, or more impressive GitHub s...  ( 8 min )

If you've ever found yourself drowning in back-and-forth scheduling emails or confused by time zone mix-ups, you’ve probably used (or wished for) a tool like Calendly. Now you can learn how to build your own version from scratch. This course is perfe...  ( 4 min )

The CSS if() function was recently implemented in Chrome 137, making it the first instance where we have it supported by a mainstream browser. Let's poke at it a bit at a very high level. Lightly Poking at the CSS if() Function in Chrome 137 originally published on CSS-Tricks, which is part of the DigitalOcean family. You should get the newsletter.  ( 10 min )

Have you ever wondered how your fridge knows when to cool, or how a coffee machine knows when to stop pouring? Behind the scenes, these devices are powered by embedded systems – small, dedicated computers designed to perform specific tasks reliably a...  ( 24 min )

Kubernetes networking is one of the most critical and complex parts of running containerized workloads in production. This tutorial will walk you through both the theory as well as some hands-on examples and best practices for mastering Kubernetes ne...  ( 18 min )

Imagine having a web app that looks and feels just like a native mobile app. It launches from your home screen, runs in full-screen mode, and responds smoothly to your interactions. But here’s the surprising part: it wasn’t downloaded from an app sto...  ( 21 min )

Zell discusses refactoring the Resize, Mutation, and Intersection Observer APIs for easier usage, demonstrating how to implement callback and event listener patterns, while highlighting available options and methods. A Better API for the Intersection and Mutation Observers originally published on CSS-Tricks, which is part of the DigitalOcean family. You should get the newsletter.  ( 10 min )

On her quest to teach you how to code vectors by hand, Myriam Frisano’s second installment of a `path` deep dive explores the most complex aspects of SVG’s most powerful element. She’ll help you understand the underlying rules and function of how curves and arcs are constructed. By the end of it, your toolkit is ready to tackle all types of tasks required to draw with code — even if some of the lines twist and turn.  ( 18 min )

If you run a website or web app, you’ve probably heard about firewalls. But there’s a special kind just for websites called a Web Application Firewall, or WAF. Think of it like a bouncer at the door of your site, checking every visitor to make sure ...  ( 7 min )

Motion graphics are no longer just eye candy. They have become a key part of how users experience software, whether it’s a mobile app, a website, or even for making animated explainer videos. When users tap a button, they expect it to respond smooth...  ( 7 min )

One of the most common questions I’m asked is, “how can I get started in technical writing?” And honestly, I love that question because it means more people are beginning to see writing as a valid, valuable way to enter the tech industry. Begin with ...  ( 12 min )

In this guide, you'll build a full server-side rendered (SSR) authentication system using Astro, Supabase, and Cloudflare Turnstile to protect against bots. By the end, you'll have a fully functional authentication system with Astro actions, magic li...  ( 11 min )

Assigning Dataverse security roles manually works pretty well – until it doesn't. Whether you are onboarding 50 new hires or rolling out access to a new app, managing roles by hand can be tedious and error-prone. In this article, you will learn about...  ( 6 min )

On this week's episode of the podcast, freeCodeCamp founder Quincy Larson interviews Kelly Vaughn. She's a self-taught software engineer who ran her own developer agency. She was also the founding CTO at financial technology startup. Kelly runs the p...  ( 3 min )

An introduction to "Color spaces", "Color models", "Color gamuts," and basically all of the "Color somethings" in CSS. Color Everything in CSS originally published on CSS-Tricks, which is part of the DigitalOcean family. You should get the newsletter.  ( 13 min )

Writing documentation looks easy, but it is one of the most critical parts of your customer support and growth strategy. Too often, teams treat it as an afterthought – just add a few code snippets and move on. But if you’re serious about product adop...  ( 10 min )

In programming, being able to find the area of a triangle is useful for many reasons. It can help you understand logic-building and syntax, and it’s a common programming problem used in school assignments. There are also many real-world applications,...  ( 10 min )

Have you ever dreamed of ordering a coffee in a Berlin café, navigating the Munich U-Bahn with ease, or simply connecting with German-speaking friends and family? Now you can take the first step towards that dream with a comprehensive and completely ...  ( 4 min )

CSS has a number of functions that can be used to set, translate, and manipulate colors. Learn what they are and how they are used with a bunch of examples to get you started. CSS Color Functions originally published on CSS-Tricks, which is part of the DigitalOcean family. You should get the newsletter.  ( 22 min )

CSS can be unpredictable — and specificity is often the culprit. Victor Ayomipo breaks down how and why your styles might not behave as expected, and why understanding specificity is better than relying on `!important`.  ( 17 min )

PHP loops help you repeat a block of code based on a condition. You can use them to work through arrays or repeat actions. You can also use them to skip steps based on logic. In this article, you will learn how PHP loops work and when to use each  ( 11 min )

When I was beginning to learn about networks, I didn't know how many things in my daily life depended on them – from texting on WhatsApp to watching YouTube. I still vividly remember when I learned that computers communicate with one another. It was ...  ( 46 min )

Meet “Accessible UX Research,” our upcoming book to make your UX research inclusive. Learn how to recruit, plan, and design with disabled participants in mind. Print shipping in August 2025. eBook available for download later this summer. Pre-order the book.

Modern chat applications are increasingly incorporating voice input capabilities because they offer a more engaging and versatile user experience. This also improves accessibility, allowing users with different needs to interact more comfortably with...  ( 12 min )

In an age of information overload, AI assistance, and rapid technological change, the ability to think clearly and reason soundly has never been more valuable. This handbook takes you on a journey from fundamental logical principles to their practica...  ( 52 min )

Are you ready to transform your career and become a data-driven decision maker? We’re excited to announce that freeCodeCamp.org has just published a comprehensive Google Cloud Data Analytics course on our YouTube channel. The course was developed by ...  ( 5 min )

How do you stay informed of new CSS features when the language evolves quickly and information is spread all around the web? Sacha Greif has some tips from his work running an annual survey focused on new CSS features. How to Keep Up With New CSS Features originally published on CSS-Tricks, which is part of the DigitalOcean family. You should get the newsletter.  ( 10 min )

Observability is a game-changer for CI/CD pipelines, and it’s one of the most exciting aspects of DevOps. When I started working with CI/CD systems, I assumed the hardest part would be building the pipeline. But with increasingly complex setups, the ...  ( 47 min )

Networking is an essential part of any Linux system. Proper networking allows communication between devices and the internet. Understanding the network interface is vital when setting up servers, solving connectivity issues, and managing device traff...  ( 9 min )

A queue is a collection of items arranged in a First-In-First-Out (FIFO) order. This means that the first item added is the first to be removed, much like a supermarket line where customers are served in the order they arrive. In this hands-on tutor...  ( 20 min )

Chat applications let you talk in real-time with your friends, family, or coworkers, and help you quickly, effectively, and efficiently transfer of information. When you’re building modern web applications, chat applications are now pretty much a req...  ( 26 min )

Python is a high-level, general-purpose programming language. Created by Guido van Rossum and first released in 1991, Python is known for its design philosophy that emphasizes code readability, notably using significant indentation. It supports multi...  ( 5 min )

Hey campers! The freeCodeCamp community is still very hard at work on the rest of the coursework for our full stack curriculum. It’s only been a few months, but already there are many campers going full-force through these new lessons and programming...  ( 4 min )

Hey friends! The freeCodeCamp team is still very hard at work on the rest of the content for our full stack curriculum. It’s only been a few months, but there are many campers who have been going full force at this new content. And I am excited to sh...  ( 4 min )

[Accessible Rich Internet Applications (ARIA)](https://www.w3.org/WAI/standards-guidelines/aria/) is an inevitability when working on web accessibility. That said, it’s everyone’s first time learning about ARIA at some point.  ( 32 min )

ResizeObserver, MutationObserver, and IntersectionObserver enhance performance over their predecessors. Zell discusses their API similarities, usage steps, refactoring strategies, and advantages with practical examples. A Better API for the Resize Observer originally published on CSS-Tricks, which is part of the DigitalOcean family. You should get the newsletter.  ( 10 min )

NestJS is a progressive Node.js framework for building efficient, reliable, and scalable server-side applications. Combining the best ideas from OOP (Object-Oriented Programming), FP (Functional Programming), and FRP (Functional Reactive Programming)...  ( 39 min )

In today's digital age, the demand for accessible and accurate health information is higher than ever. Leveraging the power of artificial intelligence, we can create intelligent chatbots that provide reliable health-related guidance. This beginner's ...  ( 12 min )

Vue composables are a very helpful tool when developing Vue applications. They give developers an easy way to reuse logic across our applications. In addition to allowing for “stateless” logic (things like formatting or routine calculations), composa...  ( 9 min )

We use our phones for everything  –  texting, banking, browsing, tracking our health, even unlocking our homes. But with all that convenience comes a lot of risk. Apps are hungry for your data. Hackers are always looking for cracks in your security. ...  ( 7 min )

If you’re serious about machine learning and want to break into real-world ML engineering, learning MLOps is one of the best things you can do. It’s what turns experiments into reliable systems. You can train a great model, but without the right pipe...  ( 4 min )

We put it to the test and it turns out Sass can replace JavaScript, at least when it comes to low-level logic and puzzle behavior. With nothing but maps, mixins, functions, and a whole lot of math, we managed to bring our Tangram puzzle to life, no JavaScript required. Breaking Boundaries: Building a Tangram Puzzle With (S)CSS originally published on CSS-Tricks, which is part of the DigitalOcean family. You should get the newsletter.  ( 16 min )

Across platforms, behind every app, and on your own website, hackers may patiently wait. These days, everyone should have identity theft protections, and be informed about data threats lurking in the trenches of the world-wide-web’s war on privacy a...  ( 23 min )

Whether you’ve just gained access to a new Linux system, ethically hacked into one as part of a security test, or you’re just curious to know more about your current machine, this article will guide you through the process. You’ll learn how you can g...  ( 22 min )

In this tutorial, Blake Lundquist walks us through two methods of creating the “moving-highlight” navigation pattern using only plain JavaScript and CSS. The first technique uses the `getBoundingClientRect` method to explicitly animate the border between navigation bar items when they are clicked. The second approach achieves the same functionality using the new View Transition API.  ( 14 min )

In this handbook, I’ll demystify the Apple app code signing process. Apple's ecosystem is powerful, but its distribution mechanisms – with various identifiers, certificates, and profiles – can appear complex. This guide attempts to make that journey ...  ( 23 min )

Vercel is a cloud platform or Platform-as-a-Service (PaaS) designed to help frontend developers create, preview, and deploy web applications swiftly and efficiently. In this tutorial, we’ll focus on deploying a Next.js application to Vercel using Git...  ( 6 min )

If you’ve been meaning to learn full-stack web development but don’t know where to start, this new course is a solid way in. Whether you're aiming to get a job in web dev or just want to build your own projects, understanding how the pieces fit toget...  ( 4 min )

The HTML popover attribute transforms elements into top-layer elements that can be opened and closed with a button or JavaScript. Popovers can be dismissed a number of ways, but there is no option to auto-close them. Preethi has a technique you can use. Creating an Auto-Closing Notification With an HTML Popover originally published on CSS-Tricks, which is part of the DigitalOcean family. You should get the newsletter.  ( 9 min )

SVG is easy — until you meet `path`. However, it’s not as confusing as it initially looks. In this first installment of a pair of articles, Myriam Frisano aims to teach you the basics of ` ` and its sometimes mystifying commands. With simple examples and visualizations, she’ll help you understand the easy syntax and underlying rules of SVG’s most powerful element so that by the end, you’re fully able to translate SVG semantic tags into a language `path` understands.  ( 16 min )

This is the third article in a series about the CSS shape() function. We've covered drawing lines and arcs in previous articles and, this time, we look specifically at the curve command and how to use it for drawing complex shapes. Better CSS Shapes Using shape() — Part 3: Curves originally published on CSS-Tricks, which is part of the DigitalOcean family. You should get the newsletter.  ( 13 min )

On this week's episode of the podcast, freeCodeCamp founder Quincy Larson interviews former CTO and prolific programming teacher Hitesh Choudhary. We talk about: The limits of AI in building a robust codebase Time management Higher Education in ...  ( 3 min )

Working remotely gives your team flexibility, but it also opens the door to cyber threats. Remote workers are more exposed without the protection of office firewalls and on-site IT teams. Hackers know that people often use weak passwords, forget to ...  ( 7 min )

Technical debt refers to the future cost – measured in terms of time, money, effort, or opportunity – of choosing expedient solutions today instead of more deliberate and scalable ones. And it's not just a pro-code concept. It might be easier to unde...  ( 11 min )

Over the years, in my role as a lead full-stack developer, solutions architect, and mentor, I’ve been immersed in the world of micro frontend architecture, working across different large-scale frontend projects where multiple teams, stacks, and deplo...  ( 26 min )

When building microservices with Spring Boot, you’ll have to decide how the services will communicate with one another. The basic choices in terms of protocols are Messaging and REST. In this article we’ll discuss tools based on REST, which is a comm...  ( 6 min )

Have you ever wanted to go beyond ‘hello world’ and build a real, production-style CI/CD pipeline – starting from scratch? Let’s pause for a moment: what are you trying to learn from your DevOps journey? Are you focusing on GitOps-style deployments, ...  ( 17 min )

The contrast-color() function doesn’t check color contrast, but rather it outright resolves to either black or white (whichever one contrasts the most with your chosen color). Safari Technology Preview recently implemented it and we explore its possible uses in this article. Exploring the CSS contrast-color() Function… a Second Time originally published on CSS-Tricks, which is part of the DigitalOcean family. You should get the newsletter.  ( 11 min )

The State of CSS 2025 Survey dropped a few days ago, and besides anticipating the results, it's exciting to see a lot of the new things shipped to CSS reflected in the questions. The State of CSS 2025 Survey is out! originally published on CSS-Tricks, which is part of the DigitalOcean family. You should get the newsletter.  ( 6 min )

We often spotlight wireframes, research, or tools like Figma, but none of that moves the needle if we can’t collaborate well. Great UX doesn’t happen in isolation. It takes conversations with engineers, alignment with product, sales, and other stakeholders, and the ability to listen, adapt, and co-create. That’s where design becomes a team sport, and when your ability to capture the outcomes multiplies the UX impact.  ( 16 min )

Making games is one of the best ways to learn programming. It pushes you to think logically, stay organized, and solve real problems. Plus, it’s just fun. If you're looking to improve your C programming skills and learn how to create a complete game ...  ( 4 min )

Godot is an open-source, lightweight, and powerful game engine. This course will teach you how to use it to bring your game ideas to life. We just published a course on the freeCodeCamp.org Spanish YouTube channel that will guide you step by step thr...  ( 4 min )

Learning general chemistry is one of the most important steps you can take if you're planning to study science in any serious way. Chemistry is foundational. It connects to biology, physics, environmental science, engineering, medicine, and so much m...  ( 4 min )

What’s the best way to make your SVGs faster, simpler, and more manageable? In this article, pioneering author and web designer Andy Clarke explains the process he relies on *to* prepare, optimise, and structure SVGs for animation and beyond.  ( 15 min )

So, how can you take dialogue box design beyond the generic look of frameworks and templates? How can you style them to reflect a brand’s visual identity and help to tell its stories? Here’s how I do it in CSS using ::backdrop, backdrop-filter, and animations. Getting Creative With HTML Dialog originally published on CSS-Tricks, which is part of the DigitalOcean family. You should get the newsletter.  ( 10 min )

Ever feel like your AI tools are a bit...well, passive? Like they just sit there, waiting for your next command? Imagine if they could take initiative, break down big problems, and even work together to get things done. That's exactly what LLM agents...  ( 20 min )

A complete frontend monitoring system is essential for tracking application performance, errors, and user behavior. It consists of three main components: data collection and reporting, data processing and storage, and data visualization. This article...  ( 28 min )

Designers love to craft, but polishing pixels before the problem is solved is a time-sink. This article pinpoints the five traps that lure us into premature detail — being afraid to show rough work, fixing symptoms instead of causes, solving the wrong problem, drowning in unactionable feedback, and plain fatigue — then hands you a four-step rescue plan to refocus on goals, ship faster, and keep your craft where it counts.

Free Wi-Fi feels like a small win when you’re out. Coffee shops, airports, and hotels offer it like candy  –  just tap, connect, and you’re online. But behind that convenience is a world of risk that most people never see coming. Let’s talk about wh...  ( 6 min )

A linked list is a data structure where each item, called a node, contains data and a pointer to the next node. Unlike arrays, which store elements in contiguous memory, linked lists connect nodes that can be scattered across memory. In this hands-on...  ( 49 min )

Most of us use Google Maps without thinking twice. You open the app, check which route has the least traffic, and hit start. Then somewhere along the way – maybe you miss a turn (I do that often) – and Maps calmly recalculates your route, showing you...  ( 15 min )

Designing for neurodiversity means recognizing that people aren’t edge cases but individuals with varied ways of thinking and navigating the web. So, how can we create more inclusive experiences that work better for everyone?  ( 11 min )

Let’s kick off June — and the beginning of summer — with some fresh inspiration! Artists and designers from across the globe once again tickled their creativity to welcome the new month with a new collection of desktop wallpapers. Enjoy!  ( 17 min )

The perceptron is a fundamental concept in deep learning, with many algorithms stemming from its original design. In this tutorial, I’ll show you how to build both single layer and multi-layer perceptrons (MLPs) across three frameworks: Custom class...  ( 23 min )

Microfrontends are transforming how teams build and deploy frontend applications at scale. This tutorial explores the architectural landscape, from traditional approaches to modern Module Federation implementations. By the end, you'll be equipped to ...  ( 12 min )

I have written articles on different platforms including LinkedIn, The Network Bits (Substack), and freeCodeCamp. So I wanted to bring all of these articles together in a single place where someone could go and see all my work. A blog sounded like a ...  ( 21 min )

Recently, I was working on a PowerApps Component Framework (PCF) project that required sorting an array of objects by date. The dates were in ISO 8601 format but without a time zone – for example, "2025-05-01T15:00:00.00". Without much thought, I wro...  ( 6 min )

On this week's episode of the podcast, freeCodeCamp founder Quincy Larson interviews Joe Attardi. He's a software engineer and prolific author of programming books. We talk about: How software development has changed over the past 21 years Tips for s...  ( 3 min )

This is the second part of a series that dives deep into the CSS shape() command, continuing with a more detailed look at the arc command. Better CSS Shapes Using shape() — Part 2: More on Arcs originally published on CSS-Tricks, which is part of the DigitalOcean family. You should get the newsletter.  ( 13 min )

It may seem like an oxymoron when the words "LeetCode" and "meditation" are used together – after all, one thing that almost everyone can agree is that LeetCode is challenging. It's called grinding LeetCode for a reason. It doesn't have anything to d...  ( 52 min )

Data science has become one of the most sought-after skills in today's technology-driven world. Whether you're looking to advance your career, make data-driven decisions, or simply understand the patterns hidden in everyday information, Python offers...  ( 4 min )

After soaking in everything shared at GoogleIO, I can’t lie – I feel supercharged! From What’s New in Flutter to Building Agentic Apps with Flutter and Firebase AI Logic, and the deep dive into How Flutter Makes the Most of Your Platforms, it felt li...  ( 38 min )