Lovable deployment

CORS Error in Production Blocking Supabase Requests

API requests to Supabase fail with CORS error in production. 'Access-Control-Allow-Origin' header missing or not matching domain. Works locally but fails on deployed site.

CORS policy requires server to explicitly allow requests from client domain. Browser blocks cross-origin requests without proper headers.

Error Messages You Might See

Access-Control-Allow-Origin header is missing CORS policy blocked request The value of the Access-Control-Allow-Origin is not a match
Access-Control-Allow-Origin header is missingCORS policy blocked requestThe value of the Access-Control-Allow-Origin is not a match

Common Causes

  1. Supabase project not configured to allow production domain
  2. Using wrong domain in CORS settings (www vs non-www)
  3. Production domain not in Supabase allowed origins list
  4. Missing API key or using wrong key tier
  5. localhost still in allowed origins blocking production domain

How to Fix It

In Supabase dashboard > Project Settings > API > CORS config, add your production domain:

https://yourdomain.com
https://www.yourdomain.com
http://localhost:5173

Use exact domains. Wildcards not allowed. Redeploy after updating.

Real developers can help you.

Daniel Vázquez Daniel Vázquez Software Engineer with over 10 years of experience on Startups, Government, big tech industry & consulting. Taufan Taufan I’m a product-focused engineer and tech leader who builds scalable systems and turns ideas into production-ready platforms. Over the past years, I’ve worked across startups and fast-moving teams, leading backend architecture, improving system reliability, and shipping products used by thousands of users. My strength is not just writing code — but connecting product vision, technical execution, and business impact. Tejas Chokhawala Tejas Chokhawala Full-stack engineer with 5 years experience building production web apps using React, Next.js and TypeScript. Focused on performance, clean architecture and shipping fast. Experienced with Supabase/Postgres backends, Stripe billing, and building AI-assisted developer tools. Kingsley Omage Kingsley Omage Fullstack software engineer passionate about AI Agents, blockchain, LLMs. Richard McSorley Richard McSorley Full-Stack Software Engineer with 8+ years building high-performance applications for enterprise clients. Shipped production systems at Walmart (4,000+ stores), Cigna (20M+ users), and Arkansas Blue Cross. 5 patents in retail/supply chain tech. Currently focused on AI integrations, automation tools, and TypeScript-first architectures. Pratik Pratik SWE with 15+ years of experience building and maintaining web apps and extensive BE infrastructure Victor Denisov Victor Denisov Developer Luca Liberati Luca Liberati I work on monoliths and microservices, backends and frontends, manage K8s clusters and love to design apps architecture Antriksh Narang Antriksh Narang 5 years+ Experienced Dev (Specially in Web Development), can help in python, javascript, react, next.js and full stack web dev technologies. Alvin Voo Alvin Voo I’ve watched the tech landscape evolve over the last decade—from the structured days of Java Server Pages to the current "wild west" of Agentic-driven development. While AI can "vibe" a frontend into existence, I specialize in the architecture that keeps it from collapsing. My expertise lies in the critical backend infrastructure: the parts that must be fast, secure, and scalable. I thrive on high-pressure environments, such as when I had only three weeks to architect and launch an Ethereum redemption system with minimal prior crypto knowledge, turning it into a major revenue stream. What I bring to your project: Forensic Debugging: I don't just "patch" bugs; I use tools like Datadog and Explain Analyzers to map out bottlenecks and resolve root causes—like significantly reducing memory usage by optimizing complex DB joins. Full-Stack Context: Deep experience in Node.js and React, ensuring backends play perfectly with mobile and web teams. Sanity in the Age of AI: I bridge the gap between "best practices" and modern speed, ensuring your project isn't just built fast, but built to last.

You don't need to be technical. Just describe what's wrong and a verified developer will handle the rest.

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Frequently Asked Questions

Do I need CORS in development?

No, Supabase allows localhost origins by default. Only needed for production domains.

Should I use wildcard CORS?

No, specify exact domains for security. Supabase does not support wildcard origins.

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Can't fix it yourself?
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You don't need to be technical. Just describe what's wrong and a verified developer will handle the rest.

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