Which AI hallucinates the most?
Asked "Which AI hallucinates the most?", ChatGPT named 17 distinct names across 10 answers on September 8, 2026, and 9 of them in two or more answers.
Measured acrossChatGPT
9 of 17 names confirmed · named in 2 or more of 10 answers · asked September 8, 2026 · 1 engines
The AI model that hallucinates the most depends on the task, benchmark, and model version, but smaller, less fine-tuned models tend to hallucinate more than larger, retrieval-augmented systems.
- 1OpenAInamed in 4 of 10 answers
'%3e%3c/path%3e%3cpath%20d='M20.616%2010.835a14.147%2014.147%200%2001-4.45-3.001%2014.111%2014.111%200%2001-3.678-6.452.503.503%200%2000-.975%200%2014.134%2014.134%200%2001-3.679%206.452%2014.155%2014.155%200%2001-4.45%203.001c-.65.28-1.318.505-2.002.678a.502.502%200%20000%20.975c.684.172%201.35.397%202.002.677a14.147%2014.147%200%20014.45%203.001%2014.112%2014.112%200%20013.679%206.453.502.502%200%2000.975%200c.172-.685.397-1.351.677-2.003a14.145%2014.145%200%20013.001-4.45%2014.113%2014.113%200%20016.453-3.678.503.503%200%20000-.975%2013.245%2013.245%200%2001-2.003-.678z'%20fill='url(%23lobe-icons-gemini-1-_R_0_)'%3e%3c/path%3e%3cpath%20d='M20.616%2010.835a14.147%2014.147%200%2001-4.45-3.001%2014.111%2014.111%200%2001-3.678-6.452.503.503%200%2000-.975%200%2014.134%2014.134%200%2001-3.679%206.452%2014.155%2014.155%200%2001-4.45%203.001c-.65.28-1.318.505-2.002.678a.502.502%200%20000%20.975c.684.172%201.35.397%202.002.677a14.147%2014.147%200%20014.45%203.001%2014.112%2014.112%200%20013.679%206.453.502.502%200%2000.975%200c.172-.685.397-1.351.677-2.003a14.145%2014.145%200%20013.001-4.45%2014.113%2014.113%200%20016.453-3.678.503.503%200%20000-.975%2013.245%2013.245%200%2001-2.003-.678z'%20fill='url(%23lobe-icons-gemini-2-_R_0_)'%3e%3c/path%3e%3cdefs%3e%3clinearGradient%20gradientUnits='userSpaceOnUse'%20id='lobe-icons-gemini-0-_R_0_'%20x1='7'%20x2='11'%20y1='15.5'%20y2='12'%3e%3cstop%20stop-color='%2308B962'%3e%3c/stop%3e%3cstop%20offset='1'%20stop-color='%2308B962'%20stop-opacity='0'%3e%3c/stop%3e%3c/linearGradient%3e%3clinearGradient%20gradientUnits='userSpaceOnUse'%20id='lobe-icons-gemini-1-_R_0_'%20x1='8'%20x2='11.5'%20y1='5.5'%20y2='11'%3e%3cstop%20stop-color='%23F94543'%3e%3c/stop%3e%3cstop%20offset='1'%20stop-color='%23F94543'%20stop-opacity='0'%3e%3c/stop%3e%3c/linearGradient%3e%3clinearGradient%20gradientUnits='userSpaceOnUse'%20id='lobe-icons-gemini-2-_R_0_'%20x1='3.5'%20x2='17.5'%20y1='13.5'%20y2='12'%3e%3cstop%20stop-color='%23FABC12'%3e%3c/stop%3e%3cstop%20offset='.46'%20stop-color='%23FABC12'%20stop-opacity='0'%3e%3c/stop%3e%3c/linearGradient%3e%3c/defs%3e%3c/svg%3e)
'%20transform='translate(0%201)'%3e%3c/path%3e%3cpath%20d='M6.726%2020.16A2.528%202.528%200%20009.152%2022h1.566c1.37%200%202.49-1.1%202.525-2.48l.17-6.69-.357%201.228a2.528%202.528%200%2001-2.423%201.83h-4.32l-1.54-.842-1.667.843h.497c1.124%200%202.113.75%202.426%201.84l.697%202.432z'%20fill='url(%23lobe-icons-copilot-1-_R_0_)'%20transform='translate(0%201)'%3e%3c/path%3e%3cpath%20d='M15%200H6.252c-2.5%200-4%203.331-5%206.662-1.184%203.947-2.734%209.225%201.75%209.225H6.78c1.13%200%202.12-.753%202.43-1.847.657-2.317%201.809-6.359%202.713-9.436.46-1.563.842-2.906%201.43-3.742A1.97%201.97%200%200115%200'%20fill='url(%23lobe-icons-copilot-2-_R_0_)'%20transform='translate(0%201)'%3e%3c/path%3e%3cpath%20d='M15%200H6.252c-2.5%200-4%203.331-5%206.662-1.184%203.947-2.734%209.225%201.75%209.225H6.78c1.13%200%202.12-.753%202.43-1.847.657-2.317%201.809-6.359%202.713-9.436.46-1.563.842-2.906%201.43-3.742A1.97%201.97%200%200115%200'%20fill='url(%23lobe-icons-copilot-3-_R_0_)'%20transform='translate(0%201)'%3e%3c/path%3e%3cpath%20d='M9%2022h8.749c2.5%200%204-3.332%205-6.663%201.184-3.948%202.734-9.227-1.75-9.227H17.22c-1.129%200-2.12.754-2.43%201.848a1149.2%201149.2%200%2001-2.713%209.437c-.46%201.564-.842%202.907-1.43%203.743A1.97%201.97%200%20019%2022'%20fill='url(%23lobe-icons-copilot-4-_R_0_)'%20transform='translate(0%201)'%3e%3c/path%3e%3cpath%20d='M9%2022h8.749c2.5%200%204-3.332%205-6.663%201.184-3.948%202.734-9.227-1.75-9.227H17.22c-1.129%200-2.12.754-2.43%201.848a1149.2%201149.2%200%2001-2.713%209.437c-.46%201.564-.842%202.907-1.43%203.743A1.97%201.97%200%20019%2022'%20fill='url(%23lobe-icons-copilot-5-_R_0_)'%20transform='translate(0%201)'%3e%3c/path%3e%3cdefs%3e%3cradialGradient%20cx='85.44%25'%20cy='100.653%25'%20fx='85.44%25'%20fy='100.653%25'%20gradientTransform='scale(-.8553%20-1)%20rotate(50.927%202.041%20-1.946)'%20id='lobe-icons-copilot-0-_R_0_'%20r='105.116%25'%3e%3cstop%20offset='9.6%25'%20stop-color='%2300AEFF'%3e%3c/stop%3e%3cstop%20offset='77.3%25'%20stop-color='%232253CE'%3e%3c/stop%3e%3cstop%20offset='100%25'%20stop-color='%230736C4'%3e%3c/stop%3e%3c/radialGradient%3e%3cradialGradient%20cx='18.143%25'%20cy='32.928%25'%20fx='18.143%25'%20fy='32.928%25'%20gradientTransform='scale(.8897%201)%20rotate(52.069%20.193%20.352)'%20id='lobe-icons-copilot-1-_R_0_'%20r='95.612%25'%3e%3cstop%20offset='0%25'%20stop-color='%23FFB657'%3e%3c/stop%3e%3cstop%20offset='63.4%25'%20stop-color='%23FF5F3D'%3e%3c/stop%3e%3cstop%20offset='92.3%25'%20stop-color='%23C02B3C'%3e%3c/stop%3e%3c/radialGradient%3e%3cradialGradient%20cx='82.987%25'%20cy='-9.792%25'%20fx='82.987%25'%20fy='-9.792%25'%20gradientTransform='scale(-1%20-.9441)%20rotate(-70.872%20.142%201.17)'%20id='lobe-icons-copilot-4-_R_0_'%20r='140.622%25'%3e%3cstop%20offset='6.6%25'%20stop-color='%238C48FF'%3e%3c/stop%3e%3cstop%20offset='50%25'%20stop-color='%23F2598A'%3e%3c/stop%3e%3cstop%20offset='89.6%25'%20stop-color='%23FFB152'%3e%3c/stop%3e%3c/radialGradient%3e%3clinearGradient%20id='lobe-icons-copilot-2-_R_0_'%20x1='39.465%25'%20x2='46.884%25'%20y1='12.117%25'%20y2='103.774%25'%3e%3cstop%20offset='15.6%25'%20stop-color='%230D91E1'%3e%3c/stop%3e%3cstop%20offset='48.7%25'%20stop-color='%2352B471'%3e%3c/stop%3e%3cstop%20offset='65.2%25'%20stop-color='%2398BD42'%3e%3c/stop%3e%3cstop%20offset='93.7%25'%20stop-color='%23FFC800'%3e%3c/stop%3e%3c/linearGradient%3e%3clinearGradient%20id='lobe-icons-copilot-3-_R_0_'%20x1='45.949%25'%20x2='50%25'%20y1='0%25'%20y2='100%25'%3e%3cstop%20offset='0%25'%20stop-color='%233DCBFF'%3e%3c/stop%3e%3cstop%20offset='24.7%25'%20stop-color='%230588F7'%20stop-opacity='0'%3e%3c/stop%3e%3c/linearGradient%3e%3clinearGradient%20id='lobe-icons-copilot-5-_R_0_'%20x1='83.507%25'%20x2='83.453%25'%20y1='-6.106%25'%20y2='21.131%25'%3e%3cstop%20offset='5.8%25'%20stop-color='%23F8ADFA'%3e%3c/stop%3e%3cstop%20offset='70.8%25'%20stop-color='%23A86EDD'%20stop-opacity='0'%3e%3c/stop%3e%3c/linearGradient%3e%3c/defs%3e%3c/svg%3e)
- 2Googlenamed in 3 of 10 answers
- 3Anthropicnamed in 3 of 10 answers
- 4GPT-3named in 2 of 10 answers
- 5Claudenamed in 2 of 10 answers
- 6LLaMAnamed in 2 of 10 answers
- 7GPT-4named in 2 of 10 answers
- 8Gemininamed in 2 of 10 answers
- 9Metanamed in 2 of 10 answers
- 10ChatGPTnamed in 1 of 10 answersone answer
- 11DeepSeeknamed in 1 of 10 answersone answer
- 12Perplexitynamed in 1 of 10 answersone answer
- 13Claude 3.5named in 1 of 10 answersone answer
- 14Groknamed in 1 of 10 answersone answer
- 15PaLMnamed in 1 of 10 answersone answer
- 16BioGPTnamed in 1 of 10 answersone answer
- 17MedPaLMnamed in 1 of 10 answersone answer
LOCKED
The full measurement
- The position each of the 1 engines gave all 17 names.
- How many of the 10 answers named each of them.
- 4 sampled observations behind this ranking, and where the engines disagree.
- Fan-out — the query each engine actually searched.
- Every citation, and the sources nobody cited.