Modern Web Guidance
A skill collection published by Google's Chrome team, together with the Microsoft Edge, Mozilla Firefox and MDN teams, under Apache 2.0 for the code and CC-BY 4.0 for the guides. It covers about 250 recent web platform features: CSS layout (container queries, `subgrid`, `oklch` colors), view transitions, popovers and anchor positioning, dialogs, form validation, performance (preloading, `scheduler.yield`), accessibility, and the AI APIs built into the browser. The agent does not load everything: it queries a small command-line tool that searches offline for the relevant guide and injects only that one, with the code, known pitfalls and a lightweight fallback for older browsers. Browser support comes from Baseline data. Still-experimental features stay searchable but locked until you allow them in a `.mwgrc` file. A second, optional pack covers Chrome extensions. You install it with one `npx` command, or through the plugin system of Claude Code, Codex and other agents.
Strengths
- Maintained by the Chrome, Edge, Firefox and MDN teams: not one vendor's taste
- Light on context: the agent pulls only the useful guide, and the skill itself fits in a few hundred tokens
- Each guide gives a lightweight fallback instead of a heavy compatibility library
- One command spots the old patterns to modernize in your code, before you even ask for a change
Limitations
- Telemetry on by default: install counts, agent name and search queries go to Google until you set `DISABLE_TELEMETRY=1`
- It covers the web platform, not your design system: it knows nothing about your in-house components
- The `npx ...@latest` command fetches the newest release on every call: two runs a week apart can give different advice
Best for
- Front-end teams that let an agent write the interface and want native HTML and CSS rather than dependencies
- A designer prototyping with an agent who wants animations, popovers and forms that hold up without extra JavaScript
- An old project to modernize: the scan command lists outdated patterns before you hand the job to an agent