Posts tagged #web-apis

Your app already runs in five tabs at once, and they all think they are in charge. The Web Locks API gives the browser a real mutex so only one of them does the work.

Custom elements can be real form controls. Here is how formAssociated, ElementInternals, and setValidity retire the hidden-input hack for good.

Chrome 148 ships experimental support for filling HTML placeholders out of order and streaming markup into the DOM. Here's how the new template-for and streamHTML APIs work, and what they replace.

Next.js 16 gave cache invalidation two different functions instead of one, and the split maps to a real distinction: content that can lag versus content the user just typed.

Firefox 148 shipped Trusted Types in February 2026, making it Baseline. Here's how to turn every dangerous innerHTML assignment in your app into a TypeError you can actually catch.

Your field data says INP is 400ms. Your local profile says everything is fine. The Long Animation Frames API closes that gap by naming the script, the function, and the character position that stalled the frame.

The contrast-color() function went Baseline in April 2026 and kills the luminance-math helper every design system eventually writes. Here is how it works, the mid-tone problem nobody warns you about, and how to work around it.

The browser can now strip XSS from an HTML string during parsing. Here's how setHTML works, why its config can only narrow the allowlist, and how to ship it before Safari catches up.

CSS sibling-index() and sibling-count() turn an element's position into a number you can drop into calc(), replacing walls of nth-child rules and inline JavaScript for staggered animations and math-driven layouts.