Hallucinations will continue to afflict generative AI in 2025.

Judged at the end of 2025. True: throughout 2025 leading generative AI systems still produced hallucinations or confabulations in a meaningful way. Evidence can include hallucination benchmarks, vendor system cards reporting non-trivial hallucination rates, and documented incidents such as fabricated citations in court filings or false outputs from AI products. A fall in rates that leaves hallucinations widespread still counts as true. Mostly false: hallucinations had become rare and marginal in leading systems by 2025. False: hallucination was effectively solved in the major systems during 2025.

Set before the research began.

1. E1 Are AI Hallucinations Getting Better or Worse? We Analyzed the Data ScottGraffius.com (Scott M. Graffius) · 7 January 2026

   “OpenAI’s o3 series, for example, experienced hallucination rates of 33-51% on PersonQA and SimpleQA.”

2. E2 Are AI Hallucinations Getting Better or Worse? We Analyzed the Data ScottGraffius.com (Scott M. Graffius) · 7 January 2026

   “Several top models dropped below 1%, including Google’s Gemini-2.0-Flash at roughly 0.7%, with OpenAI and Gemini variants clustering around 0.8–1.5% (Vectara, 2025; AllAboutAI, 2025).”

3. E3 California issues historic fine over lawyer’s ChatGPT fabrications CalMatters · 22 September 2025

   “The fine appears to be the largest issued over AI fabrications by a California court and came with a blistering opinion stating that 21 of 23 quotes from cases cited in the attorney’s opening brief were made up.”

4. E4 OpenAI o3 and o4-mini System Card OpenAI · 16 April 2025

   “The o4-mini model underperforms o1 and o3 on our PersonQA evaluation. This is expected, as smaller models have less world knowledge and tend to hallucinate more.”

OpenAI's April 2025 o3/o4-mini system card says o4-mini underperforms on its PersonQA hallucination evaluation, and that smaller models "tend to hallucinate more" (E4). An independent review reports hallucination rates of 33–51% for the o3 series on PersonQA and SimpleQA (E1). In September 2025 a California court fined a lawyer after finding that 21 of 23 case quotes in a brief were made up (E3). Some top models had hallucination rates below 1% in figures citing Vectara (E2), but that does not show hallucination was solved or rare in leading systems, so the criteria's "true" condition is met.