PhantomBench - Entities (Existence): 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 whether the concept 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 whether the concept 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
1Qwen 3 14B3.5#1233
2GPT-OSS-20B (Medium)3.93#1147 (GPT-OSS-20B)
3Qwen 3 8B4#1830
4Qwen 2.5 7B Instruct4.08#2564
5GPT-OSS-20B (Low)4.68#1147 (GPT-OSS-20B)
6Gemma 2 9B (IT)7.16#2262
7Llama 3.1 8B Instruct7.41#4246
8Qwen 3 4B7.5#2281
9Qwen 3 32B8#960
10Qwen 3 1.7B13.59#5520
11DeepSeek R1 Distill Qwen 32B15.2#1788
12Mistral 7B Instruct (v0.3)17.09#6653
13Gemini 2.5 Flash22.25#453
14Gemini 2.5 Pro29.33#266
15Gemma 3 12B (IT)47.5#1837

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