GPT-6.1 Sol
GPT-6.1 Sol is an API-only (closed weights) language model from OpenAI, released September 29, 2026. The context window is 1.1M tokens. On the Epoch Capabilities Index it scores 168.5, rank 5 of 256 rated models. API price: $2 input / $10 output per million tokens.
We’re introducing GPT‑6.1 Sol, an upgrade to GPT‑6 Sol that nearly matches GPT‑6 Astra’s intelligence on agentic coding, computer use, and professional work at one-fifth of Astra’s standard input and output token prices.
Check it against your own PC →
Strengths by category
ModelTape's 0–100 fit on Epoch AI benchmark results.
| Category | Score | Based on |
|---|---|---|
| Reasoning | 51.6 | Chess Puzzles, SimpleBench, Mystery Game Puzzles |
| Math | 81.4 | ProofBench, OTIS Mock AIME 2024-2025, FrontierMath-Tiers-1-3-v2-Private, FrontierMath-Tier-4-v2-Private |
| Knowledge | 83.9 | GPQA diamond, SimpleQA Verified |
Benchmark results
| Benchmark (Epoch AI) | Score |
|---|---|
| OTIS Mock AIME | 100.0% |
| FrontierMath-Tier-4-v2-Private | 100.0% |
| ProofBench | 99.0% |
| FrontierMath (Tiers 1–3) | 98.6% |
| GPQA Diamond | 97.8% |
| SimpleBench | 79.5% |
| Mystery Game Puzzles | 78.0% |
| SimpleQA Verified | 73.9% |
| Furniture Assembly | 71.4% |
| Chess Puzzles | 66.3% |
| MirrorCode | 61.1% |
| EBR-bench | 54.3% |
| SpireClimb | 23.8% |
Links
Announcement · Epoch AI benchmarks
Models with a similar score
Gemini 4 Carbon · GPT-6 Astra · Claude Opus 5.5 · GPT-6.1 Terra · Claude Fable 5.1 · Claude Sonnet 5.5 · Gemini 4 Argon · Claude Opus 5
More from OpenAI
GPT-6.1 Terra · GPT-6 Sol · GPT-6 Luna · GPT-6 Astra · GPT-5.6 Cyber · Daybreak Red · Daybreak Blue · GPT-5.6 Sol