Modern Web Guidance 1.0: The web platform expertise your coding agent is missing

Modern Web Guidance is now stable! Upgrade your coding agents with expert-vetted web development best practices. Read the announcement . Modern Web Guidance 1.0: The web platform expertise your coding agent is missing Stay organized with collections Save and categorize content based on your preferences. Philip Walton X GitHub LinkedIn Mastodon Bluesky Homepage Published: November 10, 2026 In this new era of agentic web development, developers expect their coding agents to be experts at building for the web. And while the latest frontier coding models are quite capable and can usually produce something that works, if you ask a web development expert to review the AI-generated code, they can almost always find ways to make the code faster, more accessible, or more secure. Chrome is investing heavily in the future of agentic web development, and to address this challenge, we introduced an early preview of Modern Web Guidance at Google I/O in May. Modern Web Guidance is a set of skills that embed web platform expertise, best practices, and browser compatibility data directly into your coding agents. Today we're excited to announce the stable release of Modern Web Guidance version 1.0, which includes: New modernization workflow that scans your existing codebase to help your agent find opportunities to safely modernize. Expanded guide database targeting hundreds of verified AI knowledge gaps with expert-vetted, cross-browser solutions. Deeper human expert review for every guide, including sign-off from content area tech leads and a dedicated accessibility review on our user-facing guides. Full evaluation coverage across all of our guides with a public eval dashboard showing the measurable improvements compared to agents without Modern Web Guidance. With version 1.0, we're also excited to share that Modern Web Guidance is becoming a cross-browser effort, with Firefox and Edge joining Chrome to support, improve cross-browser compatibility, and contribute to the project. Building on our shared work with Baseline , our goal is to ensure that anyone coding with an agent can take full advantage of the power and capabilities of the modern web platform. Regardless of what models or agent harnesses you're using, if you're building for the web, Modern Web Guidance belongs in your agentic workflow. To install Modern Web Guidance, run this command from your project directory: npx modern-web-guidance@latest install Or if you already installed an earlier version, you can update to 1.0 by running: npx modern-web-guidance@latest update For additional installation instructions or to learn more, check out the Modern Web Guidance documentation , or watch this video for a brief overview: Why developers and businesses should use Modern Web Guidance It's undeniable that coding agents have helped developers write code faster than ever before. But in a world where everyone is using coding agents, speed is no longer a competitive advantage. These days, it's more important than ever to differentiate on fundamental factors like usability and quality of experience. Here are a few ways Modern Web Guidance can help: Reinforce best practices that models often miss While frontier coding models do have a good grasp on many best practices, our evals show that there are still a number of important areas where they fall short, such as: Accessibility: Keyboard focus and inert management, reduced-motion support, and accessible form validation. User experience: Swipe and touch gestures, dialog and popover transitions, and light/dark theme implementations. Performance: Main-thread task scheduling, offscreen rendering isolation, and layout shift prevention. Security: Safe HTML sanitization, strict Content Security Policies, and passkey credential management. Accessibility best practices are particularly important to get right because mistakes like bad ARIA can make a page less accessible than no ARIA at all. For version 1.0, our user-facing guides were reviewed and tested with real assistive technologies by accessibility experts who rely on them every day. Use the best web feature for the job AI models are very good at figuring out how to make something work with JavaScript, but in many cases, there are HTML or CSS features that can do the same thing with much less code. And since they're handled by the browser, they usually perform better and come with accessibility affordances. For example: Features to animate popovers and dialogs Features to enhance scroll- and swipe-based interactions Better APIs for smooth and fluid page transitions New features can also improve the experience of a site in ways that matter to users. For example: Passkeys and WebAuthn: For faster and more secure login experiences Autofill: To improve checkout flows (especially on mobile) that often fail when using custom JavaScript-based form controls Modern Web Guidance is designed to recommend the best feature for the job, based on your browser support requirements. Its guides have embedded Baseline and browser compatibility data, so it can tailor its recommendations to your project's needs. Scan your codebase and find opportunities to modernize Most web development doesn't happen in brand-new projects. It happens in existing codebases that have accumulated years of outdated workarounds, unnecessary dependencies, and polyfills that are no longer needed. Version 1.0 adds a new modernization workflow that can analyze your existing HTML, CSS, JavaScript, and package.json to find opportunities to safely upgrade, and then guide your agent through the changes. /modern-web-guidance Modernize the code in this directory In this first release, the modernization workflow uses static analysis to check for a limited set of patterns. We chose to start with a narrow scope that yields predictable results, and then expand from there. Over time, we plan to cover many more areas, including agentic audits where your agent reasons about your code directly instead of just matching known patterns. Stay up to date as the web platform evolves The web platform is a moving target. New features ship in browsers every milestone, and existing features that you perhaps couldn't use before are becoming Baseline with each new browser release. Since Modern Web Guidance is built on top of Baseline compatibility data, and its recommendations are maintained by browser engineers, web standards experts, and accessibility specialists, these recommendations evolve along with the platform itself, and now your project can too. Learn about new web features and best practices While Modern Web Guidance is primarily built as a tool for agents, one thing we've heard from many developers is that they've actually found the guidance to be quite useful on its own—as a learning resource. Even in this era of agentic coding, there's still value in building up domain expertise. And Modern Web Guidance can help you do that: either by reading the guides themselves, or using the CLI to search use cases and discover new techniques that may be relevant to your project. Pair Modern Web Guidance with Chrome DevTools for agents In agentic web development, authoring code is only one part of the workflow. You also need to run that code to ensure it works as expected. This is why we recommend developers use Modern Web Guidance along with Chrome DevTools for agents . Modern Web Guidance gives your agent the up-front expertise needed to write code following modern best practices. Chrome DevTools for agents gives your agent runtime visibility so it can verify, debug, and optimize that code across a wide range of device capabilities, user preferences, and network conditions. Together these help your agent arrive at a better solution in fewer turns. Next are a few examples of how you can use these tools together to maximize effectiveness: Optimize until you hit your performance target Mode