I Built a Free Broken Link Checker — Paste Any URL, Find Every Dead Link

The Problem

Broken links hurt your SEO ranking and frustrate visitors. Most link checkers either:

• Require signup
• Limit free scans to 5 pages
• Take forever

The Solution

I built LinkCheck — paste any URL, get instant results.

How it works:

1. Enter any URL
2. It crawls the page, extracts every link (up to 200)
3. Checks each link in parallel with a concurrency pool of 10
4. Streams results in real-time — you see broken links appear as they're found

What it checks:

• HTTP status codes — 404s, 500s, 301 redirects
• Timeouts — links that don't respond within 8 seconds
• Connection failures — DNS errors, refused connections

Technical details:

• Built with Next.js App Router + Tailwind CSS
• Uses NDJSON streaming for real-time results
• HEAD requests first, falls back to GET
• 60-second max runtime on Vercel

Try it

https://linkcheck-kappa.vercel.app

Free. No signup. No limits.

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Part of my free developer tools collection. More at manja316.gumroad.com