What You'll Learn
Your app broke. Don't panic. This happens to everyone — even professional developers spend half their time fixing bugs.
The difference between someone who quits and someone who ships is knowing how to find and fix the problem. This guide teaches you exactly that, no coding knowledge required.
Step 1: Open the Browser Console
Every browser has a built-in error log. Here's how to open it:
F12 or right-click anywhere → "Inspect" → click the "Console" tabCmd + Option + CF12 → click "Console"Red text = errors. Yellow text = warnings (usually safe to ignore). You don't need to understand the code — you just need to copy the red text.
Try this: Open the console on any website right now. You'll probably see errors even on professional sites. Errors are normal.
How to Read an Error Message
Error messages look scary but follow a pattern. Here's what to look for:
Example error:
TypeError: Cannot read properties of undefined (reading 'name')
at UserProfile (UserProfile.tsx:24)- Breaking it down:
- TypeError — the type of error (don't worry about memorizing these)
- Cannot read properties of undefined — the actual problem in plain-ish English
- UserProfile.tsx:24 — the file and line number where it broke
You don't need to understand the code. You need to copy the entire error message and paste it to the AI. That's your entire job.
The 3-Step Debugging Prompt
When something breaks, use this exact prompt format:
I'm seeing this error: [paste the error message from the console] I was trying to: [describe what you were doing when it broke] Here's what I've already tried: [list any fixes you attempted] Fix this error. Explain what caused it in one sentence.
This works because it gives the AI three things: the symptom (the error), the context (what you were doing), and the history (what you've tried). Without all three, the AI guesses — and guesses wrong.
Pro tip: Always paste the full error message, not a summary. "It says something about undefined" is useless. The exact text is what the AI needs.
5 Most Common Vibe Coding Errors
1. Blank White Screen
Usually a build error or missing import. The app crashed before it could render anything. Check the console — there's almost always a red error explaining what's missing.2. "Cannot read properties of undefined"
The code is trying to use data that hasn't loaded yet. This usually means a database query failed or data is being accessed before it arrives. Tell the AI to add a loading state or null check.3. 404 on a Page That Should Exist
A routing issue. The page file exists but the URL doesn't match. Check that your file name matches the URL you're visiting. In Next.js,app/dashboard/page.tsx = /dashboard.
4. Form Submits but Data Doesn't Save
The frontend works but the database connection is broken. Check if your Supabase (or other database) credentials are set up correctly. This is almost always an environment variable issue.5. Works in Preview but Breaks When Deployed
Missing environment variables in your hosting platform. Your local.env file doesn't automatically transfer to Vercel/Netlify. You need to add each variable manually in the deployment settings.
When to Start Fresh vs. When to Iterate
Here's the honest truth: if you've sent 5+ prompts trying to fix the same bug, you're probably making it worse. Each fix attempt can introduce new bugs.
The better approach: revert to before the bug appeared and try a completely different approach. "Undo" is free in Lovable. Git revert is free in Cursor. Chasing a bug through 10 prompts is expensive and frustrating.
- Signs you should start fresh on a feature:
- ☐You've sent 5+ prompts about the same issue
- ☐The AI keeps "fixing" it but creating new problems
- ☐You don't understand what any of the fixes are doing
- ☐The fix requires changing more than 2 files
Pro tip: Before trying to fix anything, tell the AI: "Don't change anything else. Only fix this one specific issue: [issue]." This prevents cascading changes that break other features.
When You're Truly Stuck
Some bugs are genuinely hard. If you've tried the steps above and you're still stuck, try the Error Fixer tool. Paste your error message, get a plain-English explanation and suggested fix.
You can also try describing the problem from scratch in a new chat or prompt session. Sometimes the AI gets confused by a long conversation history, and a fresh start with a clear description works better.
Built by Us
This guide is based on real builds. gptsters.com is built with vibe coding — see for yourself.