How I Built a Free SEO Audit Tool with Next.js, Supabase, and Stripe in 1 Week

A free instant SEO audit tool called SiteGrade was built using Next.js, Supabase, and Stripe in just 1 week. The tool gives a website an A–F letter grade and top fixes ranked by impact. The author chose a boring stack to focus on the audit logic, and the total monthly infrastructure cost at zero traffic is ~$0. The tool can be used by anyone to check their website's SEO, and the author hopes to make it a useful resource for website owners.