Tools

Official Next.js plugin shipped in the vercel/next.js repo: guides enabling and tuning Cache Components and Partial Prefetching, and verifies changes on a running dev server with the Next.js MCP and agent-browser.

Official Chrome plugin bundling the Chrome DevTools MCP with debugging skills for accessibility, LCP and memory leaks: lets agents drive and inspect a real Chrome and analyze network requests, console logs and performance traces. Collects usage stats by default; can be disabled.

React and Next.js performance rules from Vercel's engineering team: 70 rules ranked by impact covering request waterfalls, bundle size, server performance and re-renders, for writing, reviewing and refactoring. Maintained by Vercel.

Official web auditing tool from the Google Chrome team: score pages on performance, accessibility, best practices and SEO from the command line and get HTML, JSON or CSV reports, so agents can iterate on a page. Needs Node 22+ and Chrome.

SVG optimizer CLI and Node.js library: shrinks SVGs by removing editor metadata, comments, hidden elements and redundant attributes, processes whole directories recursively, and gives fine control through plugin config.

GSAP's official animation skills: teach agents to use the core API, timelines, ScrollTrigger and plugins correctly, including React, Vue and Svelte integration and animation performance. Maintained by GreenSock; all plugins are free.

Lossy PNG compression CLI: converts images to 8-bit PNGs that keep transparency, usually 60-80% smaller, with batch processing and a quality range setting. Handy for slimming down web assets, slides and article images. Install via Homebrew on macOS; no account.

Font toolkit: pyftsubset subsets fonts to the characters you use and outputs WOFF2 to shrink web fonts, and ttx converts fonts to editable XML for inspection and edits. Needs Python 3.11+ and the woff extra for WOFF2; check the license before subsetting commercial fonts.

Runs Google Lighthouse across an entire site (sampling similar pages smartly) and summarizes SEO, performance and accessibility scores page by page in a local web UI; unlighthouse-ci writes reports directly for agents to read. Great for site-wide SEO checkups. Needs Node.js 22.18+.

Measurement-first audits and optimization of web quality using Lighthouse, Chrome DevTools performance traces and CrUX data, covering Core Web Vitals, WCAG 2.2 accessibility, SEO and best practices, for any frontend framework. By Addy Osmani (not an official Google project).

Gives agents on-demand guidance for the modern web platform, covering View Transitions, container queries, Popover, INP optimization, accessibility and more, with browser compatibility data so they avoid outdated code. Maintained by the Google Chrome team; currently in preview.

Diagnoses page-load and interaction performance from Chrome DevTools traces, network evidence and source code, covering Core Web Vitals, LCP and layout shifts. Separates measured values from estimates and hypotheses, and re-measures fixes under equivalent conditions.

Guides building small always-on WebGL visuals (avatars, ambient orbs, glass and iridescent surfaces) inside product UI: one shared context, a single capped frame loop, cheap fragment shaders, context-loss handling, a mandatory non-WebGL fallback, and React SSR and Server Components pitfalls.