Modern Web Guidance 1.0 Upgrades AI Coding

This is a pragmatic attempt to fix a real weakness in AI-generated frontend code: models often know modern APIs exist but still reach for familiar, bloated JavaScript patterns.

• –Covers hundreds of browser features, including dialog, Popover, CSS Highlights, container queries, and auto-sizing fields
• –Routes targeted guidance into agents’ context instead of stuffing entire documentation sets into prompts
• –The new legacy scan can identify upgrade opportunities in HTML, CSS, JavaScript, and package dependencies
• –Public browser- and AST-based evals provide stronger evidence than vague claims that an agent “writes better code”
• –Cross-browser stewardship from Chrome, Edge, Firefox, and MDN could make the guidance more trustworthy and interoperable