PhantomBench - Entities (Place): leaderboard

PhantomBench (2026) asks language models about generated terms and entities that do not exist, verified absent from a 2.3-trillion-token corpus, and counts answers that invent content instead of abstaining, as labeled by a Gemini 2.5 Flash judge. This board is the hallucination rate in percent on 1,200 non-existent entities such as events, holidays, elections, disasters and creative works, when the prompt asks where it was discovered or took place, presupposing it exists; lower is better.

Metric: Hallucination rate (%): share of answers that do not abstain on the Phantom-E subset (1,200 generated non-existent entities: events, holidays, elections, disasters, creative works and places), verified absent from the 2.3-trillion-token Dolma corpus, when the prompt asks where the concept was discovered or took place (presupposing it exists); a Gemini 2.5 Flash judge labels abstention; reasoning-model rates count only generations that reached a final answer; lower is better. Source: arxiv.org. 16 models tracked.

Top models

#ModelScoreOverall rank
1Llama 3.1 8B Instruct3.67#4246
2Qwen 2.5 7B Instruct12.25#2564
3Qwen 3 14B16.08#1233
4Qwen 3 8B18.59#1830
5Gemma 2 9B (IT)24.42#2262
6Qwen 3 4B24.84#2281
7Qwen 3 1.7B33.25#5520
8Mistral 7B Instruct (v0.3)35.16#6653
9Gemini 2.5 Pro36.17#266
10Gemini 2.5 Flash40.34#453
11Qwen 3 32B43.09#960
12DeepSeek R1 Distill Qwen 32B63.95#1788
13GPT-OSS-20B (Medium)67.53#1147 (GPT-OSS-20B)
14GPT-OSS-20B (Low)80.39#1147 (GPT-OSS-20B)
15Gemma 3 12B (IT)85.17#1837

Interactive version: theaggregate.ai/benchmark?slug=phantombench-entities-place · How It Works · Data refreshed daily, snapshot 2026-11-13.