Build a Website Loading Speed Test with Claude Code

Build a Website Loading Speed Test web app. People search for "website loading speed test" about 1,900 times a month, plus related searches like "page speed test", "website speed checker", "site performance test". The goal is a tool that ranks for those searches and makes money.

What it should do:
Build a website speed test tool with URL input and global testing locations. Show loading time metrics, performance scores, and waterfall charts. Include optimization suggestions for images, CSS, JavaScript, and server response. Add mobile/desktop testing and historical tracking. Display Core Web Vitals and detailed performance breakdown. Focus on getting basic speed testing working first.

How to build it:
1. Read this folder first. If it is empty, set up Next.js (App Router, TypeScript, Tailwind). Write a short PLAN.md with the pages, components, any library or API you need, and what you are leaving for later. Then build.
2. Put the tool itself on the homepage so a visitor can use it within seconds, with no sign-up. Do the processing in the browser where you can, so it is fast and cheap to run. Look at how Google PageSpeed Insights, GTmetrix, Pingdom do it and make ours simpler and faster.
3. Make it rank. Use "website loading speed test" in the title tag, H1 and meta description. Under the tool, add a short how-to and an FAQ with FAQPage schema, and add a sitemap and robots.txt. Scaffold these programmatic pages from one template and a data file: /speed-test-[website-type], /performance-check-[platform], /loading-time-[industry].
4. Monetisation: Freemium: 10 tests/day, $9/mo unlimited + monitoring. Add a pricing page and the free usage limit, and leave Stripe checkout as a clearly marked stub with the environment variables it needs.
5. Run it locally and test the main flow end to end, including edge cases like empty input and very large files. Fix what breaks, then finish with a summary of what works, what is stubbed and how to deploy it to Vercel.

Paste it into Claude Code in an empty folder. It plans first, so read PLAN.md and steer before it starts building.