How do I ask Lovable to diagnose an error without changing anything?
Last checked 31 Aug 2026
Short answer
Use Plan mode, or explicitly tell Lovable in Chat to investigate and explain the cause without editing code — this stops it from making speculative changes while you're still working out what's wrong.
Why this matters
Lovable's default in Build mode is to act on your request, which can mean it edits code while trying to diagnose a problem. If the diagnosis is wrong, you've now got an unrelated change to undo as well as the original bug.
How to do it
- Plan mode is built for this: it reasons about a request and produces a plan/explanation without touching code until you approve.
- In regular chat, be explicit:
Don't change any code yet. Investigate why [describe the issue], check the relevant logs/console output, and tell me what you think the root cause is.
- If Lovable does start proposing a fix, you can stop and ask it to explain its reasoning first before applying anything.
What to include for a useful diagnosis
- The exact error text (console or Logs).
- What you did right before it happened.
- Whether it's new or has always been broken.
- Any recent changes (features added, integrations connected).
What usually goes wrong
- Skipping this step and asking for a fix immediately often works fine for simple bugs, but for anything backend-related (auth, RLS, payments) a wrong guess can cascade into a bigger mess.
- People assume Plan mode is slower and skip it, when in practice one correct diagnosis is faster than three wrong fixes.
- Not confirming the diagnosis matches the actual symptom before approving a fix — read Lovable's explanation, don't just click through.
Once you agree with the diagnosis, follow up by asking for the smallest possible fix rather than a broad rewrite — see the related question on that.
Sources
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