Firefox 146 brings WebDriver BiDi updates setExtraHeaders for auto request header injection Node context locating for iframes Locale timezone override improvements Better network data collection Reliable request IDsRelease notes https: developer.mozilla.org en-US docs Mozilla Firefox Releases 146

   ✠Meet Shrinivass, a Sr Full Stack Engineer from USA, contributing for over a year improving docs like :has() and DOMContentLoaded.He says, I contribute because it’s mentorship at scale. Each improvement helps thousands of devs. Huge thanks https: developer.mozilla.org en-US community spotlight...

   Mastering layout Mastering FlexboxTest your understanding with MDN’s hands-on Flexbox exercises. No setup needed, just code and see what happens, with interactive scrims ✠’ Learn by solvinghttps: developer.mozilla.org en-US docs Learn web development Core CSS layout Test your skills Flexbox

   Firefox 146 ships improvements for CSS devs contrast-color() for WCAG-friendly contrast display-p3-linear color space text-decoration-inset scope at-rule now on by default -webkit-fill-available for better compatRelease notes https: developer.mozilla.org en-US docs Mozilla Firefox Releases 146

   Fine-tune multilingual typography with text-autospace ✠It lets you control spacing between CJK and Latin characters.> text-autospace: ideograph-alpha ideograph-numeric punctuation;Now available on Baseline 2025. Learn more https: developer.mozilla.org en-US docs Web CSS Reference Properties...

   ’ Not a designer? No problem.If you're a developer who wants to build better-looking interfaces, this guide is made for you. It covers:✠Visual design principles✠Color, contrast, and typography✠Layout✠Visual hierarchy and balanceRead now https: developer.mozilla.org en-US docs Learn web...

   Firefox 146 is out What's new: Inspector: auto-hides unused CSS custom properties contrast-color() text-decoration-inset support scope enabled by default WeakMap WeakSet now accept Symbol keys WebDriver BiDi upgradesRelease notes https: developer.mozilla.org en-US docs Mozilla Firefox Releases...

   Ever wish HTTP status codes were easier to remember? Check out this MDN cheatsheet that pairs each status code with an emoji to help you visualize what each one means, from 200 OK ✠to 418 I’m a teapot Check it out

   Did you know about Strict Mode? ✠"use strict"; ✠Strict Mode catches silent errors, making your code more predictable and easier to debug. It also improves performance and helps you write more secure JavaScript code.See how https: developer.mozilla.org en-US docs Web JavaScript...

   Ever wonder what’s really happening behind your web images? From pixels to formats to compression, you should use:- JPEG for details- PNG for transparency- WebP & AVIF for web-performance- SVG for resolution-independent graphicsRead more https: developer.mozilla.org en-US blog image-formats...

   Ever wonder what’s really happening behind your web images? From pixels to formats to compression, you should use:- JPEG for details- PNG for transparency- WebP & AVIF for web-performance- SVG for resolution-independent graphicsRead more https: developer.mozilla.org en-US blog image-formats...

   startViewTransition() is now part of Baseline This API lets you create smooth same-document (SPA) transitions, no framework required. Perfect for page updates, theme switches, and animated UI changes.Learn how it works https: developer.mozilla.org en-US docs Web API Document startViewTransition

   Search from anywhere. Navigate like never before. The new MDN front end comes with a new search modal, refreshed UI, and better typography for docs that feel as good as they read.Take a look https: developer.mozilla.org en-US blog launching-new-front-end

   You’ve learned how to write a function... now let’s make sure it works. Practice real coding challenges with JavaScript functions - right in your browser, with interactive scrims from Scrimba. Write, run, and debug your way to masteryhttps: developer.mozilla.org en-US docs Learn web development...

   Features from <select> you should know:✠disabled prevent user interaction✠multiple allow multi-select✠size show more than one option at a time✠<optgroup> group related optionsAnd there are more https: developer.mozilla.org en-US docs Web HTML Reference Elements select

   Margin? Border? Padding? Content? ’ The CSS box model is the foundation of layout, and MDN’s interactive exercises help you truly understand how it all fits together. ’ Practice live in your browserhttps: developer.mozilla.org en-US docs Learn web development Core Styling basics Test your skills...

   Tired of hacking together deep copies with JSON.parse(JSON.stringify(...))? The structuredClone() method lets you safely clone complex JavaScript objects.No data loss. No surprises. Just clean, reliable cloning.Learn more https: developer.mozilla.org en-US docs Web API Window structuredClone

   Need a Fetch refresher? Fetch API offers cleaner, promise-based syntax, better error handling, and async await support. You can: ’ Add tokens & content types Make POST requests s Manage large data sets efficientlyLearn more https: developer.mozilla.org en-US docs Web API Fetch API Using Fetch

   ✠Imagine your site animating between pages no jarring reloads, just smooth transitions.That’s the magic of CSS View Transitions They bring SPA-like navigation effects to multi-page apps all with just a few lines of CSS Learn how in this beginner-friendly guide by Yash Raj Bharti https: developer...

   Newly Available since Firefox 140 ✠CookieStore API offers a modern, promise-based way to read, write, update, and delete cookies, all without parsing strings manually. It brings,✠Async operations✠Structured data✠Service worker supporthttps: developer.mozilla.org en-US docs Web API...