ChatGPT has become one of the most popular AI tools in the world. But how accurate is it really? Let's look at the numbers.
Overall Accuracy Rates by Model
ChatGPT's accuracy has improved significantly with each new version. Here's how the different models compare:
- GPT-3.5 (2022): 70-75% accuracy with a high hallucination rate of 39.6%
- GPT-4 (2023): 85-88% accuracy, which is 40% more factual than GPT-3.5
- GPT-5 (2025): 87-94% accuracy with 45% fewer errors than GPT-4
Domain-Specific Performance
ChatGPT performs differently depending on the subject area. Some topics are easier for it than others.
Math Performance
On the AIME 2025 math test, ChatGPT achieved 94.6% accuracy. This is one of its strongest areas.
General Knowledge
On the MMLU benchmark test for general knowledge, ChatGPT scores 87% correct answers.
Medical Questions
Physicians rated ChatGPT's medical answers as completely or mostly correct 84.8% of the time. In neurology specifically, ChatGPT outperformed human doctors with 64% accuracy compared to 60.2% for physicians.
However, there's a big catch. ChatGPT is only 16.6% accurate for rare medical conditions, compared to 86.6% for common ones.
Legal Knowledge
GPT-4 scored in the top 10% on a bar exam simulation. This is a huge improvement from GPT-3.5, which scored in the bottom 10%.
The Hallucination Problem
AI hallucinations happen when ChatGPT makes up information that sounds true but isn't. This is one of the biggest concerns with using AI.
GPT-3.5 had a citation hallucination rate of 39.6%. This means it made up fake sources almost 40% of the time.
GPT-5 is much better. It is 6 times less likely to fabricate answers compared to earlier versions. The citation hallucination rate dropped to 28.6%.
Key Limitations to Know
OpenAI itself admits that ChatGPT can make mistakes. They recommend checking important information. Here are areas where you should be especially careful:
- Current events: GPT-3.5 and GPT-4 have knowledge cutoffs at September 2021
- Rare medical conditions: Only 16.6% accurate
- Company-specific information: Often outdated or incorrect
- Regulatory compliance details: May not reflect current laws
What This Means for You
ChatGPT is getting more accurate with each version. GPT-5 shows major improvements in reducing errors and hallucinations.
For general questions and common topics, ChatGPT performs well. It excels at math and general knowledge. But for specialized or rare topics, you should always verify the information.
Businesses often get better results using specialized AI trained on their own verified data rather than relying on general models alone.
Bottom Line
ChatGPT accuracy ranges from 70% to 94% depending on the version and topic. The newer the model, the more accurate it is. Always double-check important information, especially for medical, legal, or company-specific questions.
