Lovable App Not Deploying
Your app looks perfect in Lovable's preview. Then you publish it, connect a custom domain, or move it to Vercel or Netlify, and it breaks: the build fails, pages show 404 errors, or login and data stop working. Asking the AI to fix it keeps going in circles. A Codersarts engineer gets your Lovable app live and working.
A Lovable app that works in preview but fails when deployed usually has a setup problem outside the code the AI edits: build errors that the preview tolerates, missing environment variables or backend settings on the new host, page routing that needs a hosting rule, login redirect settings still pointing to the preview domain, or backend functions and secrets that were never set up in the production Supabase project. These issues sit between tools, which is why prompting the AI rarely solves them.
Typical symptoms | Failed builds, 404 on page refresh, login broken after publishing, data not loading, custom domain errors |
Most common causes | Build errors, missing environment settings, routing rules, auth redirect URLs, backend functions not deployed |
How we fix it | Reproduce the production build, fix code and hosting setup, configure the backend, test on your live domain |
Turnaround | Same-day diagnosis; most fixes in 24–48 hours |
Price | Live Debug from $20; fixed-price quote for the full fix |
Signs Your Lovable App Has a Deployment Problem
The app works in preview but the published version shows errors or a blank page
Deploying from GitHub to Vercel or Netlify fails during the build
Pages load from the home screen but show 404 when refreshed or opened directly
Login works in preview but fails or redirects to the wrong site when live
Data, file uploads, or AI features stop working after moving to your own backend
Your custom domain doesn't connect or shows security warnings
Each AI fix attempt creates a new error
Why Lovable Apps Break When Deployed
Lovable generates a modern web app, typically React with Supabase as the backend. The preview environment handles several things for you. When the app runs somewhere else, or under a different domain, those hidden pieces need to be set up properly.
1. Build errors the preview doesn't show
A production build is stricter than a live preview. Type errors, unused or missing imports, and dependency conflicts can pass in preview and stop a real build on Vercel or Netlify. Mixed lockfiles from different package managers can also install different versions than the ones Lovable used.
2. Missing environment settings
Backend URLs, API keys, and other settings must exist on the new host. When an app moves to its own Supabase project or a new hosting provider, settings still pointing to the old project, or missing entirely, stop data and login from working.
3. Page routing on static hosting
Apps like these handle page navigation in the browser. When someone refreshes /dashboard or opens a shared link, the host looks for a file that doesn't exist and returns 404. Hosting providers need a rewrite rule that sends every route to the app.
4. Login redirects tied to the preview domain
Supabase only allows redirects to approved URLs. If the Site URL and redirect list still reference the preview address, logins, magic links, and password resets fail or send users to the wrong site after launch.
5. Backend functions and secrets not deployed
Features that call AI models, payments, or email often run as Supabase Edge Functions with their own secrets. Moving to a new Supabase project without deploying those functions, secrets, database tables, and security policies breaks those features even though the interface loads.
How We Diagnose the Deployment Failure
Confirm where it fails. Separate build failures, hosting errors, and features that break after the app loads.
Run a clean production build. Reproduce the exact error the host reports.
Compare environments. Check backend URLs, keys, and settings between preview and production.
Test routing. Open deep links and refresh pages on the deployed domain.
Review Supabase configuration. Check redirect URLs, database tables, security policies, edge functions, and secrets.
Check domain setup. Verify DNS records and SSL for your custom domain.
How We Fix It
Root cause | Fix |
Build errors | Fix type and import errors, resolve dependency conflicts, and keep a single clean lockfile |
Missing environment settings | Move keys and URLs into host environment variables and point them to the correct backend |
404 on page refresh | Add the right rewrite rule for Vercel, Netlify, or your host |
Broken login after launch | Update Supabase Site URL and redirect URLs for your live domain |
Backend features failing | Deploy edge functions, set secrets, and migrate tables and security policies to the production project |
Custom domain issues | Correct DNS records and confirm SSL is active |
Your app stays editable in Lovable. We fix the deployment without breaking your ability to keep building with it.
Example Fix
Situation: A founder built a client portal in Lovable and exported it to GitHub to host on Vercel under the company domain. The build failed, and after a partial fix, users couldn't log in and refreshing any page showed 404.
Cause: Three TypeScript errors blocked the production build, the Supabase project URL was still set to a development project, the login redirect list only included the preview domain, and Vercel had no rewrite rule for app routes.
Fix: Fixed the build errors, moved Supabase settings into Vercel environment variables, added the company domain to Supabase redirect URLs, and added a rewrite rule for all routes.
Result: The portal went live on the company domain with working logins and shareable page links.
How to Keep It From Happening Again
Test a production build before publishing big changes, not just the preview.
Keep production and development backends separate so experiments don't break live users.
Update redirect URLs whenever you add a domain, including preview and staging domains.
What You Get
Root cause explained in plain language
App live and working on your chosen host and domain
Environment and backend settings documented
Checklist for future deployments
Frequently Asked Questions
Why does my Lovable app work in preview but not when published? The preview handles builds, settings, and domains for you. Once published or moved to another host, stricter builds, missing environment settings, routing rules, and login redirect URLs all need to be set up correctly.
Why does my deployed Lovable app show 404 when I refresh a page? The hosting provider is looking for a file for that page. Apps like this need a rewrite rule that sends all routes to the app so it can load the right page.
Why did login stop working after I connected my domain? Supabase only redirects to approved URLs. Add your live domain to the project's Site URL and redirect URL settings.
Can I host my Lovable app on Vercel or Netlify? Yes. Export the code to GitHub and deploy it with the correct environment variables, build settings, and routing rules for that host.
Will I still be able to edit my app in Lovable after the fix? Yes. We keep the project compatible with Lovable so you can continue building after it's deployed.
Related Problems
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React app blank page after deployment
Get Your Lovable App Live
Share your app link or the deployment error. Get a diagnosis and a fixed price.