Prompt Debugger

Scan your prompts for logical loopholes, contradictory constraints, missing output formats, and hallucination risks before deploying to ChatGPT, Claude, or production LLM systems.

Scanner Configuration
Target Scan Area: All Vulnerabilities
FlawedOriginal Prompt3 Issues Found
“Write a product description for our app. Make it detailed but keep it short. Don't use any adjectives, but make sure it sounds exciting and vivid. Also, translate the final result into French.”
DiagnosisDebugger Output+ Fixed Logic
⚠ Contradiction — "detailed" vs. "keep it short": no length target given to resolve this.
⚠ Contradiction — "no adjectives" vs. "sounds exciting and vivid": vivid language needs descriptive words.
⚠ Scope creep — translation task bundled with content task: split into two prompts.
AI Quality Assurance & Reliability

Why Prompt Debugging is Essential for Reliable AI Responses

Unlike traditional software where code errors throw clear stack traces and compiler warnings, AI prompts fail silently. When a prompt contains subtle contradictions, missing negative constraints, or ambiguous terms, the AI model won’t notify you of an error—it will simply produce hallucinations, ignore your rules, or return broken formatting.

Prompt Debugger acts as an automated static analyzer for your instructions. By auditing your prompt against proven prompt engineering heuristics, it highlights logical loopholes and supplies copy-ready patches to guarantee rock-solid AI execution on your very first run.

4 Critical Prompt Flaws Caught by the Debugger

1

Contradictory Instructions

Asking an AI to “be extremely concise” while also instructing it to “explain all technical details thoroughly” creates an internal priority conflict that causes hallucinations.

2

Unbounded Output Scope

Commands like “give me all examples” lack stopping rules, leading to rambling responses that consume unnecessary tokens and truncate mid-sentence.

3

Missing Schema & Layout Constraints

Failing to specify exact output formats (Markdown headings, tables, JSON schemas) results in unpredictable conversational padding and messy layouts.

4

Ambiguous Pronouns & Context Gaps

Vague references like “it should do this depending on that” confuse the model’s attention heads, resulting in incorrect variable assumptions.

Common Prompt Vulnerabilities & Their Instant Fixes

Detected VulnerabilityWhat Goes WrongDebugger Recommended Patch
Vague Summary RequestAI outputs 500 words of generic prose without takeaways“Summarize into exactly 3 bullet points, max 20 words each.”
Unspecified Code FormatAI includes placeholder comments and conversational filler“Provide complete, executable code only. No placeholders or chit-chat.”
Missing Source DisciplineAI invents plausible-sounding facts when unsure“If the answer is not confirmed in context, state 'Data unavailable'.”

Frequently Asked Questions

What the Prompt Debugger does

The Prompt Debugger reads your prompt the way an AI model would and reports what is likely to go wrong: vague wording, instructions that contradict each other, missing constraints and edge cases the prompt does not cover. Each issue comes with an explanation and a suggested fix.

Use it when an AI ignores part of your instructions, gives inconsistent answers or hallucinates. It is also useful before you put a prompt into production, where a small ambiguity gets repeated thousands of times.

How to use the Prompt Debugger

  1. 1

    Paste the prompt that is not working

    Include the full prompt, including system instructions if you have them.

  2. 2

    Run the scan

    The debugger lists the issues it finds, ordered by how much they are likely to hurt the result.

  3. 3

    Read each issue

    Every finding says what is wrong, why it causes problems and how to fix it.

  4. 4

    Apply the fixes

    Apply the suggested fixes in one click, or edit by hand, then run the scan again to check.

Example: before and after

Before

Summarize this article briefly but include all the important details. Make it short. Use a professional tone but keep it casual.

After

Issues found:
1. Contradiction: "briefly" and "include all the important details" pull in opposite directions. Set a length (e.g. 3 sentences) and say what counts as important.
2. Contradiction: "professional" and "casual" tone. Pick one.
3. Missing output format: say whether you want a paragraph or bullet points.

None of these problems is obvious on a quick read, but each one makes the AI guess, and the guesses change from run to run.

Who the Prompt Debugger is for

  • Developers building with LLM APIs

    Catch ambiguity in system prompts before it reaches users.

  • Prompt engineers

    Review a prompt for contradictions and gaps without reading it ten times.

  • Everyday ChatGPT and Claude users

    Find out why the AI keeps ignoring one of your instructions.

  • Teams

    Use it as a quick review step for shared prompts.

Prompt Debugger FAQ

Why is my prompt not working?

The usual causes are conflicting instructions, vague terms like "short" or "good", missing constraints and no output format. The debugger checks for all of these.

Does the debugger rewrite my prompt?

It explains each problem and can apply the fixes for you. If you want a full rewrite instead, use the Prompt Optimizer.

Can it find hallucination risks?

It flags places where the prompt invites the model to invent facts, such as asking for details it was never given, and suggests grounding rules.

Does it work for system prompts and agent instructions?

Yes. Paste any text instruction, from a one-line request to a long system prompt.

Is the Prompt Debugger free?

Yes, with a free daily allowance. Signing in raises the limit.

Prompts to try it on

Browse the Prompt Cookbook
Code Generation & Software Engineering

ChatGPT Prompt to Debug an Error From a Stack Trace

A debug stack trace prompt gives ChatGPT, Claude, or Gemini the exact error message, the stack trace, and the relevant code so it can find t…

ROLE: You are an experienced [PROGRAMMING LANGUAGE] developer helping debug a runtime error.

CONTEXT:
- Language/runtime: [LANGUAGE AND VERSION, e.g. Python 3.11, Node 20]
- Framework/libraries involved: [FRAMEWORK NAMES AND VERSIONS]
- What the code is supposed to do: [BRIEF DESCRIPTION OF THE FEATURE OR FUNCTION]
- Error message and full stack trace:
[PASTE FULL ERROR MESSAGE AND STACK TRACE HERE, TOP TO BOTTOM, UNEDITED]

- Relevant source code (include every function/file named in the trace):
[PASTE CODE FOR EACH FRAME IN THE STACK TRACE]

- What I've already tried: [LIST ANY FIXES OR CHECKS ALREADY ATTEMPTED, OR WRITE "NOTHING YET"]

CONSTRAINTS:
- Do not suggest a fix until you've identified the specific line and condition that triggers the exception
- If the trace doesn't contain enough information to be certain, say so and list what additional information (logs, input values, config) would confirm the cause
- Do not assume framework defaults that weren't stated — ask if a detail is missing rather than guessing

OUTPUT FORMAT:
1. Root cause analysis: the most likely cause, tied to the exact line/frame in the trace
2. Alternative hypotheses: 1-2 other possible causes, ranked by likelihood, each with what evidence would confirm or rule it out
3. Suggested fix: the minimal code change to resolve the most likely cause
4. Verification step: how to confirm the fix actually resolves the error (a test to run, a log line to check, an input to retry)

Make this prompt yours

Code Generation & Software Engineering

AI Prompt to Debug a Failing API Test Using Postman's MCP Server

This prompt helps developers and QA engineers debug a failing API test by having an AI assistant like Claude or ChatGPT pull live request an…

ROLE: You are a senior API test engineer helping debug a failing test in a Postman collection accessed through an MCP connection.

CONTEXT:
- Collection name: [COLLECTION_NAME]
- Failing request/folder: [REQUEST_OR_FOLDER_NAME]
- Environment: [ENVIRONMENT_NAME]
- Last known good run (if available): [RUN_ID_OR_DATE]

TASK:
1. Retrieve the failing request's details (method, URL, headers, body) and its actual response (status code, headers, body) from the connected Postman MCP server.
2. Identify the exact assertion or test script line that failed, quoting it directly.
3. Compare the failing response against the expected response or the last known good run, and list every meaningful difference.
4. Classify the likely root cause as one of: schema change, authentication/authorization failure, timeout/network issue, environment misconfiguration, or application bug.
5. Propose a specific fix or next diagnostic step for that category.

CONSTRAINTS:
- Do not guess at response data you have not actually retrieved; if the MCP call fails, say so explicitly.
- Keep the explanation under 200 words before listing the fix.

OUTPUT FORMAT:
- Summary: [one-sentence description of the failure]
- Evidence: [key request/response fields and the failing assertion]
- Root cause category: [one of the five categories above]
- Recommended fix: [specific, actionable step]

Make this prompt yours

RAG & Knowledge Retrieval

AI Prompt to Evaluate RAG Answers for Hallucinations Against Retrieved Context

This RAG hallucination detection prompt checks a generated answer against the exact passages a retrieval augmented generation system pulled…

ROLE: You are a strict fact-checking evaluator for a retrieval-augmented generation (RAG) system. You do not answer questions or improve the answer; you only judge it.

CONTEXT:
Retrieved passages:
[PASTE THE EXACT RETRIEVED CONTEXT CHUNKS HERE, NUMBERED]

Generated answer to evaluate:
[PASTE THE RAG SYSTEM'S GENERATED ANSWER HERE]

Original user question:
[PASTE THE ORIGINAL QUESTION HERE]

TASK:
1. Break the generated answer into individual factual claims.
2. For each claim, decide whether it is:
   - SUPPORTED: directly backed by a specific passage
   - PARTIALLY SUPPORTED: related to a passage but adds unsupported detail, numbers, or certainty
   - UNSUPPORTED: no passage backs this claim, even if it sounds plausible
3. For every SUPPORTED or PARTIALLY SUPPORTED claim, cite the passage number it relies on.
4. Do not use outside knowledge to judge truth; judge only whether the provided context supports the claim.

CONSTRAINTS:
- Evaluate every claim individually; do not summarize the whole answer as one verdict
- Be skeptical of specific numbers, dates, or named entities in the answer that are not explicitly in the passages
- If a claim restates the question without adding information, mark it as NOT APPLICABLE rather than forcing a verdict

OUTPUT FORMAT:
Return a numbered list, one entry per claim, each with:
Claim: [the exact claim text]
Verdict: [SUPPORTED / PARTIALLY SUPPORTED / UNSUPPORTED / NOT APPLICABLE]
Evidence: [passage number and quote, or "none found"]

End with:
Overall hallucination rate: [X of Y claims unsupported or partially supported]
Recommendation: [APPROVE / REVISE / REJECT the answer]

Make this prompt yours

Further reading: console.log vs debugger in Node.js