Coding

Debugging

Diagnose and fix errors instead of guessing.

Knowledge cards
Concept
Ask for the Cause Before the Fix
A sequencing habit: ask ChatGPT to explain why the bug happens before it proposes a fix, and only accept the fix once the stated cause makes sense.
L2 · Context engineering
Best practice
Give a Minimal Reproduction, Not the Whole File
A debugging discipline: reduce the problem to the smallest snippet that still reproduces the bug — plus the inputs, expected output, and actual output — before asking ChatGPT to diagnose it.
L2 · Context engineering
Mistake
Debug by Pasting the Error, Not the Vibe
A debugging discipline: give ChatGPT the exact error message, the stack trace, and the smallest snippet that reproduces it — rather than describing the symptom in your own words.
L2 · Context engineering
Mistake
When It Loops on a Wrong Fix, Reset the Context
A recovery move: when ChatGPT cycles through variations of the same wrong fix, stop feeding the failing thread and open a fresh chat with a clean, well-framed statement of the problem.
L2 · Context engineering
ChatGPT debugging

Paste the error, not the vibe

The biggest single improvement to debugging with ChatGPT is to give it evidence instead of a description. Paste the exact error message, the stack trace, and the smallest snippet that reproduces the problem. 'It crashes sometimes' forces ChatGPT to guess; a stack trace and the failing function give it something concrete to reason from. The more precisely you can point at where the failure happens, the more likely the fix addresses the real cause rather than a plausible-looking symptom.

Make it explain before it fixes

A good habit is to ask ChatGPT to explain the cause of the bug before proposing a change. That forces it to commit to a theory you can sanity-check, instead of jumping to a fix that happens to compile. If the explanation is wrong, you catch it before touching the code. For subtle bugs, ask for two possible causes and how to tell them apart — that turns debugging into a quick experiment rather than a guess.

Frequently asked
How do I debug code with ChatGPT?

Paste the exact error, the stack trace, and the smallest snippet that reproduces it, rather than describing the symptom. Concrete evidence lets ChatGPT reason about the real cause instead of guessing.

Why does ChatGPT suggest fixes that don't work?

Often because it was given a description instead of the actual error, so it guessed. Ask it to explain the cause before proposing a fix, so you can catch a wrong theory before changing code.

What if ChatGPT can't find the bug?

Ask it for two competing hypotheses and the observation that would distinguish them, then test. Narrowing down with a small experiment beats accepting the first plausible-looking fix.