GPT-5.1-Codex vs GPT-5.6 Sol
GPT-5.1-Codex (OpenAI) and GPT-5.6 Sol (OpenAI) compared on benchmarks, pricing, context window, and use-case rankings.
- GPT-5.1-Codex is cheaper on input tokens — $1.25 vs $5.00 per 1M.
- GPT-5.6 Sol has a larger context window (1.1M vs 400K tokens).
- GPT-5.6 Sol ranks higher for coding (95th vs 51th percentile).
| Attribute | GPT-5.1-Codex | GPT-5.6 Sol |
|---|---|---|
| Scores | ||
| Intelligence (ECI) | — | 162 |
| Coding | 51 | 95 |
| Math | 77 | 97 |
| Reasoning & Knowledge | 60 | 95 |
| Agentic & Tools | 50 | 67 |
| Specifications | ||
| Developer | OpenAI | OpenAI |
| Family | GPT | GPT |
| Released | Nov 12, 2025 | Jul 9, 2026 |
| Parameters | — | — |
| Availability | API access | API access |
| Context window | 400K | 1.1M |
| Price — $/M input | $1.25 | $5.00 |
| Price — $/M output | $10.00 | $30.00 |
| Inputs | text, image | file, image, text |
| Outputs | text | text |
| Benchmarks | ||
| AIME 2024/2025 | 96% | 100% |
| APEX | 21% | 40% |
| GPQA Diamond | 86% | 93% |
| Humanity's Last Exam | 23% | 47% |
| LiveCodeBench | 85% | — |
| MMLU-Pro | 86% | — |
| SciCode | 40% | 56% |
| Terminal-Bench | 58% | — |
| WebDev Arena | 1331 | — |
| τ²-bench | 83% | 85% |
| ARC-AGI | — | 98% |
| ARC-AGI-2 | — | 93% |
| SimpleBench | — | 72% |
| SimpleQA Verified | — | 72% |
| WeirdML | — | 89% |
Use-case scores are 0–100 percentile composites across each area’s benchmarks, ranked against every model from the past year. Highlighted cells lead each row. Open a model for the full picture.
Frequently asked questions
Which is cheaper, GPT-5.1-Codex or GPT-5.6 Sol?
GPT-5.1-Codex is cheaper on input tokens at $1.25 per million, versus $5.00 (representative OpenRouter pricing).
Which has a larger context window, GPT-5.1-Codex or GPT-5.6 Sol?
GPT-5.6 Sol supports up to 1.1M tokens, compared with 400K for the other.
Which is better for coding, GPT-5.1-Codex or GPT-5.6 Sol?
Across coding benchmarks like SWE-bench Verified and Terminal-Bench, GPT-5.6 Sol ranks higher — 95th vs 51th percentile among the models tracked on Model Beat.
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Benchmarks & model data from Epoch AI (CC BY); pricing & specs from OpenRouter. ECI = Epoch Capabilities Index.