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What is AI Hallucination?

A hallucination is when an AI states something false or fabricated — a fake citation, statistic, or quote — with total confidence.

An AI hallucination is a confident, plausible-sounding output that is simply wrong: an invented source, a misremembered figure, a quote nobody said, or an API that doesn't exist. It happens because the model predicts likely text, not verified truth — fluent and factual are not the same thing.

You reduce hallucinations by grounding the model in data you provide (paste the source, then ask it to answer only from that), asking it to cite or flag uncertainty, and lowering temperature. You never eliminate them, so any factual claim — especially names, numbers, citations, and legal or medical statements — must be verified against a trusted source.

Frequently asked

Why does AI make up facts?

Because it generates the most probable next words based on patterns, not a database of verified truth. When it lacks the real answer, it produces a fluent, plausible guess. Fluency is not accuracy.

How do I stop AI hallucinations?

Ground it: paste the source material and instruct it to answer only from what you provided. Ask it to cite sources or say 'I don't know,' lower the temperature, and always verify names, numbers, and citations yourself.

Related terms

Put this into practice

Every technique above shows up in real, copy-paste prompts in the free Prompt Library — e.g. Finance prompts, Law prompts, Personal Finance prompts.

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Reality guardrail: definitions here are practical, not academic. AI models predict likely text, not verified truth — always check names, numbers, and citations against a trusted source before you rely on an answer.

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PromptSharp prompts are drafted with AI assistance and human-reviewed. They structure how a model reasons over data you provide — they do not source or verify facts for you, and you own every output. Nothing here is financial, legal, tax, or investment advice. Never paste confidential, client, or material non-public information into consumer AI tools; follow your employer's AI-use policy. © 2026 PromptSharp.