Prompt templates

How to stop AI making things up: 7 prompts that make it check its own work

Every AI assistant sometimes states things that aren’t true, with total confidence. You can’t switch that off, but you can make it much rarer and much easier to catch. These seven prompts come from Anthropic’s own guidance and from the checking routines careful researchers use.

By Chris · Updated Oct 6, 2026 · Facts checked Oct 2, 2026

Short answer

You can’t make AI stop hallucinating completely, but you can cut it down sharply: let it say “I don’t know”, make it quote your source before answering, make it cite or delete each claim, and ask a second AI to check anything important. Then verify the facts that matter yourself.

1. Give it permission to say “I don’t know”

Assistants are built to be helpful, so they’ll guess rather than admit a gap. Anthropic says simply allowing uncertainty “can drastically reduce false information”. Add one line to any factual question:

If you're not sure about any part of this, or the information isn't available to you, say "I don't know" for that part instead of guessing.

2. Make it quote your source before it answers

When you give the AI a document — a contract, a policy, a report — ask it to pull out the exact sentences first and answer only from those. It keeps the answer tied to the real text instead of its memory.

Here is the document: [paste]. Step 1: Copy, word for word, the sentences from the document that answer my question: [question]. Number them. If there are none, say "No relevant quotes found." Step 2: Answer my question using only those quotes, referring to them by number. Don't use outside knowledge.

3. Make it back up every claim — or delete it

After it writes something, make it audit its own claims against your material. Anything it can’t support has to go.

Review your last answer. For each factual claim, give the exact quote from my documents that supports it. If you can't find a supporting quote, remove the claim and mark where it was with [removed].

4. Run a self-audit: label where every fact came from

This is the habit careful researchers use, and it works on any topic. It forces the AI to separate what it read from what it assumed, and to point you to the weakest spots.

Self-audit your answer: 1. List every factual claim. Label each one: [From my document] / [Official source] / [News or secondary source] / [Your inference or guess]. 2. Name the 3 claims most likely to be wrong, and tell me exactly how I could check each one. 3. Check you answered every part of my question with no contradictions. Fix anything that fails.

5. Ask for a confidence level — and what would change it

An AI’s confidence number isn’t a real probability, so don’t treat “0.8” as 80%. But asking for it makes the assistant flag shaky parts, and the second question is the useful one: it tells you what evidence to look for.

End with: your confidence in this answer (low / medium / high), the main caveats, and what new information would change your conclusion.

6. Get a second opinion from a different AI

Different assistants make different mistakes, so disagreement is a useful alarm. Ask the same factual question in two of them — for example ChatGPT and Claude, or Gemini, which can check against Google Search — and look hard at anything they disagree on. Anthropic suggests the same idea within one assistant: run the prompt more than once and compare; inconsistencies are a warning sign.

To make one AI critique another’s answer, paste it in with this:

Another assistant gave this answer to my question "[question]": [paste the answer] 1. Where do you agree, and why? 2. Where do you disagree? Give specific objections and the evidence. 3. What did it miss? 4. Your own best answer, with the claims I should double-check.

Work one after the other rather than reading several answers at once: it’s easier to spot a real disagreement when you compare them side by side at the end.

7. Make it teach the topic back to you

When you’re learning something new, a “teach-back” session exposes gaps on both sides — yours and the AI’s. It’s based on the Feynman technique: explain simply, find the gaps, refine.

Teach me [topic] in plain words, as if I'm 14. Then ask me 3 questions to check I understood. Correct my answers, and point out anything in your own explanation that experts would disagree with or that you're unsure of.

What no prompt can fix

Recent events. Unless the assistant searches the web, it may not know what happened this month. Ask it to search, or paste in the source.
Exact numbers, dates and quotes. Check these against the original — a company’s filing, an official page, the actual article.
Invented links. Click every source. A real-looking link can lead nowhere, or to a page that says something else.
High-stakes decisions. Health, legal, money: use AI to prepare questions and summaries, then check with the original source or a professional.

These tips build on the four basic prompt moves in our prompting guide. If you research companies or investments, see AI prompts for stock research that don’t ask it to pick stocks.

Sources: Anthropic: Reduce hallucinations · Anthropic: prompting best practices · Wharton: “think step by step”

Quick answers

Can you stop AI from hallucinating completely?

No. Anthropic’s own guide says these techniques reduce hallucinations but “don’t eliminate them entirely”, and tells you to always check critical information yourself — especially for high-stakes decisions.

Why does AI make things up?

An assistant writes the most likely-sounding answer. When it doesn’t know, a confident guess can still sound likely, so it comes out as fact. Gaps get worse for recent events, exact numbers, quotes and niche topics.

Does asking AI for sources stop hallucinations?

It helps, but AI can invent sources too. Ask it to quote the exact sentence it relied on, then click the link and check the quote is really there.

Which AI hallucinates the least?

It changes with every model update, and no single test settles it. A safer habit is to ask two different assistants the same factual question and check anything they disagree on.

Does “think step by step” reduce hallucinations?

Not reliably with today’s “thinking” models — studies found it barely changes accuracy and slows answers down. Giving permission to say “I don’t know” and asking for quotes work better.

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