Key takeaways

• GPT-5.1 is an OpenAI text+image-to-text chatbot, designed as a smarter, more conversational version of GPT-5 for enhanced interactive AI communications and diverse content generation.
• The model employs a proprietary Mixture-of-Experts (MoE) architecture, has a 400,000 token context length, and can generate up to 120,000 output tokens.
• GPT-5.1 excels at directly implementing Python functions, achieving 94.51% accuracy on the 'Python Coding Benchmark' for tasks like list manipulations, string operations, mathematical computations, and conditional logic.
• The model struggles significantly with precise numerical computations and complex scientific interpretations, achieving only 6.19% accuracy on 'Humanity's Last Exam', often hallucinating factual details and misinterpreting problem constraints.
• Common failure modes include misinterpretation of problem constraints, numerical calculation errors in multi-step problems, difficulty resolving ambiguity, and hallucination of facts, limiting its reliability in tasks demanding absolute precision.

Technical specifications

Context length

400k tokens

Max output

—

Architecture

MoE

Modalities

text+image->text

Parameters

~1000B

Open weights

No

Licence

Proprietary

Regions

USA

Vendor

OpenAI

Provider model key

openai_gpt-5.1-2025-11-13