I Scanned 5 Popular JavaScript Sites for SEO Issues — Here's What I Found

Everyone assumes big tech companies have flawless SEO. I decided to test that. I scanned five well-known JavaScript-heavy sites — react.dev, vercel.com, stripe.com/docs, linear.app, and shopify.com — running 19 SEO health checks across 10 pages each. Every single site had issues. Some had a lot of them. The Scores react.dev — 74/100 (Best of the group) vercel.com — 71/100 (Solid but sloppy on details) stripe.com/docs — 60/100 (Surprising for Stripe) linear.app — 57/100 (Heavy SPA showing its seams) shopify.com — 39/100 (The biggest surprise) react.dev — 74/100 React's docs scored highest. Strong internal linking (3.5 avg links/page, zero orphan pages), all pages indexable, proper canonicals and OG tags. Weak spots: zero structured data on every page, meta descriptions too short on 9/10 pages, and a JavaScript file that failed to load on /versions. The irony of React's docs having a broken JS file is hard to ignore. vercel.com — 71/100 The Next.js creators get SSR right — all pages inde