PhantomBench - Entities (Meaning): 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 what it means, 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 what the concept means or refers to (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 Instruct7.92#4246
2Qwen 2.5 7B Instruct8.33#2564
3Qwen 3 14B9.92#1233
4Qwen 3 8B15.92#1830
5Gemma 2 9B (IT)20.42#2262
6Qwen 3 32B23.5#960
7Qwen 3 4B24.33#2281
8Gemini 2.5 Pro28.59#266
9Qwen 3 1.7B31#5520
10Gemini 2.5 Flash33.67#453
11Mistral 7B Instruct (v0.3)47.83#6653
12GPT-OSS-20B (Medium)57.7#1147 (GPT-OSS-20B)
13GPT-OSS-20B (Low)61.51#1147 (GPT-OSS-20B)
14DeepSeek R1 Distill Qwen 32B66.84#1788
15Gemma 3 12B (IT)85.99#1837

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