GPT-5.6 Sol
GPT-5.6 Sol by OpenAI is the frontier model in the GPT-5.6 family for complex professional work across coding, research, science, and cybersecurity.
Model Overview
Capabilities, design details, and architectural traits
GPT 5.6 Sol - frontier model for complex professional work
GPT 5.6 Sol is the frontier model in the GPT 5.6 family, positioned as OpenAI's flagship for complex reasoning and coding. It serves as the default tier - the gpt 5.6 alias routes all requests to Sol, and it roughly corresponds to the unsuffixed model tier used in earlier GPT 5 families.
The model targets complex professional work across coding, research, science, cybersecurity, computer use, and design. It supports a 1,050,000-token context window with up to 128,000 output tokens and offers six reasoning effort levels: none, low, medium, high, xhigh, and max.
Built-in tool ecosystem
Sol provides an extensive set of built-in tools through the Responses API. Beyond standard web search, file search, and computer use, it includes hosted shell for executing shell commands, apply patch for code modifications, skills for specialized task invocation, MCP for external tool integration via Model Context Protocol, and tool search for discovering available tools.
| Trait | Detail |
|---|---|
| Family position | Frontier tier in the GPT 5.6 family; the gpt 5.6 alias routes all requests here |
| Hosted shell | Built-in tool for executing shell commands in a hosted environment |
| Apply patch | Built-in tool for applying code patches directly |
| Skills | Built-in tool for invoking specialized model skills |
| MCP | Native Model Context Protocol support for external tool integration |
| Tool search | Built-in capability to discover and search available tools |
| Fine-tuning | Not supported |
Benchmark Performance
Independent evaluations · Artificial Analysis
Accuracy & Capability Details
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| Model Details | |||
|---|---|---|---|
| General Info | |||
| Provider | OpenAI | Anthropic | Anthropic |
| Release Date | July 9, 2026 | September 22, 2026 | September 28, 2026 |
| Knowledge Cutoff | Feb 2026 | - | Jun 2026 |
| Context & Limits | |||
| Context Window | 1.1M Best Context Window | 1M | 1M |
| Pricing (per 1M tokens) | |||
| Input Pricing | $4 | $4 | $2 Best Input Pricing |
| Output Pricing | $20 | $20 | $10 Best Output Pricing |
| Modalities | |||
| Inputs | textimagefile | textimagefile | textimagefile |
| Outputs | text | text | text |
| Benchmarks (0-100) | |||
| Intelligence Index | 47.0 | 57.6 Best Intelligence Index | 56.0 |
| Coding Index | 77.4 | - | - |
| Agentic Index | 50.2 | - | - |
Humanity's Last Exam
Extremely difficult logical reasoning and knowledge.
Long Context Reasoning
Logical reasoning over long context windows.
SciCode Benchmark
Scientific coding and mathematical modeling.
Independent evaluation data provided by Artificial Analysis. To view the latest benchmarks and full details, visit their official site.
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