Did you know about Clear-Site-Data header? &#&#One HTTP header to clear cookies, storage, or cache for your site. Perfect for logout flows.&#&#Learn...

   Schedule work at the right time with queueMicrotask() âs &#&#Run a callback after the current task but before rendering. More predictable than...

   Format lists like a native speaker &#&#Intl.ListFormat turns arrays into grammatically correct strings in any locale. Handles and , or , and narrow...

   Fit images perfectly with object-fit &#&#Control how replaced content (images, videos) fills its container. cover, contain, fill, scale-down, or none...

   Parse and build query strings the easy way &#&#URLSearchParams gives you a clean API for working with URL parameters. Get, set, append, delete, and...

   Happening tomorrow at Mozilla Berlin s Firefox, open source & the future of the web. Firefox Mobile open source contributions Firefox Roadmap &...

   Support dark mode with one CSS property &#&#color-scheme tells the browser your page supports light, dark, or both. Form controls, scrollbars, and...

   Server-render Shadow DOM with declarative syntax ✠&#&#Use to create shadow roots in HTML. No JavaScript required for initial render.&#&#Perfect for...

   Mozilla Meetup is back in Berlin Apr 28 18:00 Firefox, open source & the future of the web. Firefox Mobile open source contributions Firefox Roadmap...

   Transform iterators without converting to arrays &#&#Iterator helpers like .map(), .filter(), .take(), and .drop() work lazily on any iterable....

   Help us build the WebAssembly language reference on MDN &#&#We’re documenting Wasm 1.0 instructions, reference-types, and SIMD, and looking for...

   Firefox 150 is here What’s new?&#&# color-mix() accepts multiple colors&# New :playing, :paused, :muted media pseudo-classes&# œ animation-range...

   Set operations are native in JavaScript union(), intersection(), difference(), symmetricDifference() no more manual loops for set math. const a new...

   Simplify complex selectors with :is() and :where() ✠&#&#Both group selectors to reduce repetition. The difference? :is() keeps specificity, :where(...

   Want to help make Wasm more accessible? Come join us ✠&#&#[contains quote post or other embedded content]

   Responsive values without media queries &#&#clamp() sets a minimum, preferred, and maximum value in one function. Perfect for fluid typography and...

   Transform key-value pairs back into objects &#&#Object.fromEntries() is the inverse of Object.entries(). Convert Maps, arrays, or URLSearchParams...

   Use gap in flexbox, no more margin hacks &#&#The gap property works in flexbox, grid, and multi-column layouts. Set consistent spacing between items...

   Read and build form data with the FormData API &#&#Construct form submissions programmatically, including file uploads. Works with fetch() for modern...

   Control CSS specificity with layer &#&#Cascade layers let you define explicit priority between groups of styles. No more important battles.&#&#Learn...

   Split text by words and sentences, for any language &#&#Intl.Segmenter handles locale-aware text segmentation, including CJK languages where spaces...

   Write direction-aware CSS with logical properties &#&#Replace top right bottom left with block-start inline-end block-end inline-start. Your layouts...

   Cancel fetch requests and more with AbortController &#&#Create a signal, pass it to fetch(), and call abort() when needed. Works with...

   Generate cryptographically secure UUIDs in the browser &#&# crypto.randomUUID() is built into the Web Crypto API, no npm package needed.&#&#Works in...

   Search arrays from the end with findLast() &#&#Array.findLast() and findLastIndex() return the last matching element without reversing the array...

   Balance your headings automatically âs &#&#text-wrap: balance distributes text evenly across lines, preventing awkward orphan words. Perfect for...

   Mix colors directly in CSS &#&#color-mix() blends two colors in any color space. Create tints, shades, and dynamic palettes without a preprocessor...

   CSS :has() the parent selector is real Select elements based on what they contain. Style a card differently when it has an image, or a form when it...

   The element handles modals the right way &#&#Built-in focus trapping, backdrop styling, and Escape key handling. No more custom modal libraries.&#&#â...

   Smooth page transitions in the browser ✠&#&#The View Transitions API lets you animate between DOM states with a single API call. Works for SPAs...