Why I added internal linking to my image converter (and what changed in Google)

I've been building Convertify — a free image converter powered by Rust + libvips. Two weeks in, Google had indexed 18 of my 186 static pages. The numbers were moving, but slowly. Then I read a recommendation that changed my approach: internal linking is 80% of cluster SEO. The problem My converter pages existed in isolation. /heic-to-jpg had no idea /heic-to-png existed. Google couldn't see a cluster — just a collection of unrelated tools. What I built A RelatedConversions component that generates contextual links on every page: const RELATED: Record<string, string[]> = { heic: ["jpg", "png", "webp", "avif"], avif: ["jpg", "png", "webp", "heic"], // ... }; export default function RelatedConversions({ from, to }) { // generates links like "HEIC to PNG", "WEBP to JPG" etc. // deduplicates, shows related formats from both source and target } On the homepage — "Popular Conversions". On converter pages — "Related Conversions". Every page now links to 6-8 related pages. The immediate r