How I Built a Free Invoice Generator with Next.js — 47 Pages, Zero Database, $7.50 Total Cost

I built a free invoice generator that has 47 static pages, zero database, and costs $7.50/year to run. Here's how. The Stack Next.js 16 (App Router) TypeScript Tailwind CSS jsPDF (client-side PDF generation) Vercel (free tier hosting) Cloudflare ($7.50/year domain) The Architecture 47 Static Pages at Build Time I used generateStaticParams to create pages for: 15 industry-specific templates — freelance, contractor, photography, construction, plumbing, electrician, etc. Each page has sample line items, tips, and FAQs specific to that industry. 10 country pages — India (GST), UK (VAT), USA (Sales Tax), Australia (ABN/GST), UAE (TRN/VAT), etc. Each page shows local tax rules, required invoice fields, and popular payment methods. 5 how-to guides — "how to create an invoice", "how to invoice as a freelancer", "how to add tax to an invoice", etc. All statically generated. Zero runtime cost. Every page is a separate SEO target. Lazy Loading Heavy Libraries jsPDF is ~700KB. Users don't need it