fix guide
Lovable app not working: find the cause, then fix it
Harjot · · updated
Your Lovable app worked yesterday, or it works in the editor, and now the live link is blank, half broken or won't publish.
Find your symptom in step 1 and read only that step. Each one ends with the signs that tell you it's your case. For why the preview and the live app differ at all, read /guides/ai-app-works-in-preview-breaks-when-deployed. Before launch, run the checks in /guides/vibe-coded-app-security.
1. Start with the symptom
Blank white page on the live link: read step 4.
Works in the Lovable preview, breaks on the live link: read step 3.
The Publish dialog shows "Publishing failed": read step 5.
Everything was fine and nothing loads, even the editor: read step 2 first.
2. Check Lovable's status page
Open status.lovable.dev. If it shows an open incident, wait for it to close before you change anything. Fixes you make during an outage can add new bugs and won't help.
An outage looks different from a bug. Every project fails, including ones you haven't touched, and the editor itself is slow or erroring.
signs Other projects fail too, and the status page lists an incident.
3. Preview works, live breaks
Lovable's docs say publishing deploys a snapshot, and changes aren't pushed to your live app on their own. Open Publish and choose Publish changes. Accepting a draft doesn't publish it.
If the live app is on your own host, such as Vercel or Netlify, the host needs the same environment variables the project uses. A missing Supabase URL or key usually shows up as the error supabaseUrl is required. The fix is in supabaseUrl is required: blank page on your live site.
If login works in the preview and fails live, Supabase is probably still sending users back to the preview address. Add the live URL in Supabase under Authentication, then URL Configuration. More on that in Supabase login works locally but fails in production.
signs The preview shows your latest change and the live link shows an older one, or login sends you back to a preview address.
4. Blank screen after publish
A blank page means the app crashed while loading. The browser console tells you why.
Open the live link, right-click the page, choose Inspect, then open the Console tab. Reload. Read the first red line, not the last one. Later errors are often caused by the first.
Copy that line into the Lovable chat as it is, with the page it happened on. A precise error gets a better fix than "the app is blank".
signs The page is white, the tab title loads, and the console shows red errors.
5. Publish fails
The Publish dialog shows a "Publishing failed" banner, and Lovable's docs match the action to the cause. For a timeout or rate limit, click Try again. For a build error or a project setting, click Try to fix.
If a connection expired, such as Supabase, reconnect it first, then click Try again. If the failure is on Lovable's side, wait a few minutes and try again. If it keeps failing, send support your project link.
If it publishes but a page shows 404 when you refresh it on your own host, that's a routing setting, covered in 404 on refresh on Vercel. It isn't a publish failure.
signs The banner names a cause, or a page loads from the menu and 404s on refresh.
6. Before you click Try to fix again
Lovable's debugging guide suggests Try to fix once or twice, then investigate. Each extra attempt can change code that was working.
Go back to the last version that worked. Open History from the top bar (or the chat menu, under Project), pick that version and click Revert. Then change one thing and test it.
Reverting restores your code, not your database data. Lovable's docs say so, so check your tables after a revert. If rows are missing or won't save, see Supabase data not saving, no error.
Your account gets 10 free fixes, shared by Try to fix and the Security view. Each one comes back 24 hours after you use it. After that, fixes use credits.
To see what a diagnosis looks at, read the checks page. To tell a diagnosis from a full fix, read Bug diagnosis vs full fix for an AI-built app.
signs You've clicked Try to fix three or more times and the error keeps changing.
Test it like a new user
- Open the live link in a new private window, not the editor preview.
- Reload once with the console open and check there are no red lines.
- Do the main action a visitor would do: sign up, log in, save something.
- Refresh on an inner page to check it doesn't 404.
Common questions
Why does my Lovable preview work but the live link shows the old version?
Lovable publishes a snapshot, so changes aren't pushed to the live app on their own. Open Publish and choose Publish changes. Accepting a draft doesn't publish it. If login sends you back to a preview address, add the live URL in Supabase under Authentication, then URL Configuration.
Why does my Lovable live link show a blank white page after publishing?
The app crashed while loading, and the browser console says why. Open the live link, right-click the page, choose Inspect, open the Console tab and reload. Read the first red line, not the last one, and paste it into the Lovable chat as it is.
What does Lovable's Try to fix do when publishing fails with a banner?
Click the button that matches the banner's cause. For a timeout or rate limit, click Try again. For a build error or a project setting, click Try to fix. If a connection such as Supabase expired, reconnect it first, then click Try again.
Still stuck?
Not sure this is the cause? Paste your app's link into the free scan. It lists what a visitor's browser can see, like leaked keys and exposed files, worst first. The score is free; every fix as a prompt for your builder is $9, one-time.
Want a person to look inside? See the diagnosis