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GPT-5.1 Instant

OpenAI · 2025-11-12

GPT-5.1 Instant is OpenAI's conversational GPT-5.1 model, released in ChatGPT on November 12, 2025 with improved instruction following and intrinsic adaptive reasoning that decides when to think before responding. OpenAI exposed it to API developers on November 13 through the model-specific gpt-5.1-chat-latest alias; OpenAI's model page lists no separate dated snapshot.

Benchmark scores

BenchmarkScore
BullshitBench v2 Leaderboard45.0
Capability138.9
FORTRESS Average Risk Score (ARS)30.4
HealthBench (length-adjusted)49.6
HealthBench (updated implementation)50.8
HealthBench Hard (length-adjusted)21.6
HealthBench Hard (updated implementation)23.0
HealthBench Professional40.4
HealthBench Professional (Length-Adjusted)37.6
Humanity's Last Exam6.8
Humanity's Last Exam (Text Only)6.5
MASK63.3
MultiChallenge51.2
MultiNRC18.3
Ruby LLM Benchmarks — Program Fixer69.8
Ruby LLM Program Fixer — Calendar76.6
Ruby LLM Program Fixer — Parking Garage48.6
Ruby LLM Program Fixer — School Library76.3
Ruby LLM Program Fixer — Vending Machine77.5
SnakeBench Average Apples4.1
SnakeBench Best Apples12.0
SnakeBench Rating23.3
SnakeBench Total Apples66.0
SnakeBench Win Rate73.3
SpeciEval83.8
SpeciEval — Belief in Animal Sentience6.1
SpeciEval — Land Animal 4Ns3.3
SpeciEval — Sea Animal 4Ns3.8
SpeciEval — Speciesism2.4
TutorBench49.1
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