3 Hacks to Fix GPT-5 Hallucinations
ChatGPT frequently hallucinates false information—fake definitions, incorrect stats—often because users fail to set clear rules.
This short demonstrates three practical hacks to stop hallucinations: using bracketed XML-style tags to structure prompts cleanly, implementing a self-checking mode where GPT plans steps and reviews output against a checklist before finalizing, and banning outside knowledge by restricting the model to provided documents and instructing it to say 'Data not provided' when information is missing.
These techniques significantly reduce errors in ChatGPT outputs.
Yes, ChatGPT gets things wrong all the time - fake definitions, SEO stats, you name it. That’s called hallucination. But it might often happen just because you didn’t set the rules. Let me show you 3 hacks I use to stop it. First thing I do? I add bracketed tags around all the details I put in the prompt — the role, the task, the tone. Sounds a bit nerdy, I know. But OpenAI says GPT-5 actually reads XML-style tags best. It keeps your logic clean (especially if you work with long instructions), and stops the model from hallucinating. Second thing: I make the GPT check itself. First, I tell it to plan in steps it will follow before drafting (aka “thinking mode”). Then, before giving me the final draft, it has to run this quick checklist - like, is the format right, are the facts correct, does the tone fit? If it fails, it revises. One trick, way fewer mistakes. And the third trick: ban outside knowledge. Hallucinations happen when it tries to fill in the
blanks. Make GPT stick to what you give it - your docs, your product details, your rules. And then, add this: ‘If info’s missing, say Data not provided.’ That kills most of them. Want more tips like these? We’ve dropped the full guide on the SE Ranking blog.