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corscheck Verified
Instantly inspect and debug CORS headers
Screenshot of corscheck.sebastiaan-ba3.workers.devOpen website ↗
About this tool
corscheck is a free tool that lets you paste a URL to see its actual CORS headers and whether a cross-origin browser request would be allowed, with preflight simulation and misconfiguration warnings. A paid multi-origin report for 0.02 USDC on Base adds reflect-any-origin probing and ready-to-paste fix snippets for Express, Nginx, FastAPI, and Cloudflare Workers.
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