CORS Misconfiguration in Lovable App
Your Lovable app either blocks legitimate requests with CORS errors or is configured with overly permissive CORS settings (Access-Control-Allow-Origin: *) that allow any website to make requests to your API.
CORS errors appear as failed API calls in the browser console, preventing your app from communicating with its backend or third-party services. On the other hand, wildcard CORS settings mean any malicious website could make requests to your API on behalf of your users.
This commonly happens when your frontend and backend are on different domains, or when Lovable generates API routes without proper CORS configuration.
Error Messages You Might See
Common Causes
- Wildcard origin allowed — The API is configured with Access-Control-Allow-Origin: * which is insecure for authenticated endpoints
- Missing CORS headers — The backend doesn't include the necessary CORS headers, blocking frontend requests
- Credentials with wildcard — Trying to send cookies/auth headers with a wildcard CORS policy, which browsers block
- Preflight request failing — OPTIONS requests are not handled, causing complex requests (POST with JSON) to fail
- Different domains in production — Frontend and API are on different domains but CORS is only configured for localhost
How to Fix It
- Set specific allowed origins — Replace wildcard (*) with your actual frontend domain(s)
- Handle OPTIONS preflight — Make sure your server responds to OPTIONS requests with proper CORS headers
- Allow credentials properly — If using cookies/auth, set Access-Control-Allow-Credentials: true with a specific origin (not wildcard)
- Configure allowed methods and headers — Explicitly list the HTTP methods and headers your frontend needs
- Test with browser DevTools — Check the Network tab for failed preflight requests and missing headers
Real developers can help you.
Matthew Butler
Systems Development Engineer @ Amazon Web Services
Jen Jacobsen
I’m a Full-Stack Developer with over 10 years of experience building modern web and mobile applications. I enjoy working across the full product lifecycle — turning ideas into real, well-built products that are intuitive for users and scalable for businesses.
I particularly enjoy building mobile apps, modern web platforms, and solving complex technical problems in a way that keeps systems clean, reliable, and easy to maintain.
Rudra Bhikadiya
I build and fix web apps across Next.js, Node.js, and DBs.
Comfortable jumping into messy code, broken APIs, and mysterious bugs.
If your project works in theory but not in reality, I help close that gap.
Matthew Jordan
I've been working at a large software company named Kainos for 2 years, and mainly specialise in Platform Engineering. I regularly enjoy working on software products outside of work, and I'm a huge fan of game development using Unity. I personally enjoy Python & C# in my spare time, but I also specialise in multiple different platform-related technologies from my day job.
AUXLE
I am a Full Stack Developer experienced in building Websites, Web apps and Cross Platform Mobile Apps for Startups and Companies.
Bastien Labelle
Full stack dev w/ 20+ years of experience
Jared Hasson
Full time lead founding dev at a cyber security saas startup, with 10 yoe and a bachelor's in CS. Building & debugging software products is what I've spent my time on for forever
hanson1014
Full-stack developer experienced in fixing and deploying AI-generated apps from Lovable, Bolt.new, Cursor, and Replit. I specialize in debugging Supabase integration issues (auth flows, RLS policies, database connections), fixing broken deployments, resolving routing/blank screen problems, and cleaning up messy React/Vite codebases. I also build production apps with the Claude API and have shipped a Mac desktop dev tool (Nexterm from scratch. Based in Hong Kong, fast turnaround.
Meïr Ankri
Full-stack developer specializing in React / Next.js / Node.js with 6+ years of experience. I've worked across various sectors including automotive (Reezocar/Société Générale), healthcare (Medical Link SaaS), and e-commerce (Glasman). I build web apps end-to-end, from architecture to production, with a focus on scalability, performance, and code quality. I also mentor junior developers and contribute to technical decisions and code reviews.
Matt Butler
Software Engineer @ AWS
You don't need to be technical. Just describe what's wrong and a verified developer will handle the rest.
Get HelpFrequently Asked Questions
What is CORS and why does it exist?
CORS (Cross-Origin Resource Sharing) is a browser security feature that prevents websites from making requests to a different domain than the one that served the page. It protects users from malicious sites making unauthorized API calls.
Is it safe to use Access-Control-Allow-Origin: * ?
Only for public APIs that don't use authentication. For any API that handles user data or requires login, you must specify exact allowed origins.