Bootstrap 6.0.0 Alpha 1 has been released, introducing significant changes including the abandonment of support for older browsers and a complete rewrite of styles utilizing Sass modules and native browser APIs. The new browser support requires Chrome 130+, Firefox 132+, and Safari 18+, with previous fallbacks, prefixes, and polyfills no longer included. Developers will need to adapt their code to new CSS token maps and ESM-only JavaScript, as the UMD bundle and global window.bootstrap have been removed. Key components have been renamed, and while Bootstrap 5 will continue to be supported until further notice, the shift to Bootstrap 6 demands attention to ensure compatibility with the new features and requirements

Bootstrap 6 Alpha 1: Major Overhaul Drops Older Browsers and Rewrites Styles

Bootstrap 6.0.0 Alpha 1 shipped today, marking the project's first major overhaul in a year, built around Sass modules, native browser APIs, and ESM-only JavaScript. The most jarring change is the browser support floor, which climbs from Chrome 60 and Safari 12 in Bootstrap 5 to Chrome 130+, Firefox 132+, and Safari 18+ in Bootstrap 6, with all fallbacks, prefixes, and polyfills dropped. Developers will also need to rewrite styles to CSS token maps, swap infix classes for Tailwind-style prefixes, and convert to ESM-only JavaScript since the UMD bundle and window.bootstrap global are gone. Alongside the overhaul, key components have been renamed while Bootstrap 5 stays supported until an end-of-life date is announced and v5.4.0 ships first.

Bootstrap 6 Alpha 1: Major Overhaul Drops Older Browsers and Rewrites Styles @ Linux Compatible