Model Details
GPT-6 Sol
Quick answer: GPT-6 Sol is OpenAI's mid-tier successor to GPT-5.6 Sol, released alongside GPT-6 Luna on September 22, 2026, as siblings to the flagship GPT-6 Astra. It's priced 50% lower than GPT-5.6 Sol ($2/$10 per Mtok) while improving on agentic coding, computer-use, and long-horizon agent benchmarks.
What GPT-6 Sol Is
GPT-6 Sol sits between GPT-6 Astra (flagship) and GPT-6 Luna (small/cheap) in OpenAI's GPT-6 family, available via ChatGPT and Codex. OpenAI reports it matching or beating larger/costlier models like Claude Opus 5 on several agentic benchmarks at a fraction of the cost.
Specifications
| Organization | OpenAI |
| License | Proprietary (API only) |
| Release date | September 22, 2026 |
| Modality | Text |
| Knowledge cutoff | Not disclosed |
Public Benchmark Scores
| Benchmark | Score | Source | Date |
|---|---|---|---|
| Agents' Last Exam V1 | 56.4% (max effort) | OpenAI | Sep 2026 |
| DeepSWE v1.1 | 68.8% (max effort) | OpenAI | Sep 2026 |
| OSWorld 2.0 | 60.5% (xhigh effort, offline set) | OpenAI | Sep 2026 |
Scores as reported in OpenAI's own GPT-6 Sol and Luna announcement (openai.com/index/introducing-gpt-6-sol-and-luna, September 2026); not independently verified by Benchgen.