GPT-5.1 Codex High vs GPT-6.1 Sol: Specs & Benchmark Comparison
GPT-5.1 Codex High and GPT-6.1 Sol both come from OpenAI, GPT-5.1 Codex High was released in November 2025, and GPT-6.1 Sol followed 10 months later in September 2026.
We have 1 benchmark result for GPT-5.1 Codex High and 10 benchmark results for GPT-6.1 Sol, but they were measured on different benchmarks, so there is no like-for-like scoreboard.
GPT-5.1 Codex High is the cheaper API at $1.25 per million input tokens and $10 per million output tokens, about 60% below GPT-6.1 Sol at $2 and $10. GPT-6.1 Sol takes the larger context window at 1M tokens, compared with 400K for GPT-5.1 Codex High. Both accept text and images as input.
| Characteristic | GPT-5.1 Codex High | GPT-6.1 Sol |
|---|---|---|
| Company | OpenAI | OpenAI |
| Release Date | November 11, 2025 | September 29, 2026 |
| Parameters | — | — |
| Multimodal | Yes | Yes |
| Context (input) | 400K | 1.1M |
| Context (output) | 128K | 128K |
| Input Price / 1M | $1.25 | $2.00 |
| Output Price / 1M | $10.00 | $10.00 |
| Average Score | 97.0% | 58.5% |
Verdict
GPT-6.1 Sol leads in 2 out of 4 comparison categories.
Both models show comparable average scores: GPT-5.1 Codex High — 1.0, GPT-6.1 Sol — 0.6.
GPT-5.1 Codex High is 1.1x cheaper: input $1.25/1M vs $2.00/1M tokens.
GPT-6.1 Sol supports a larger context: 1M vs 400K tokens.
GPT-6.1 Sol is newer: released 9/29/2026 vs 11/11/2025.
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Frequently Asked Questions
Which is better for coding — GPT-5.1 Codex High or GPT-6.1 Sol?
Which model is cheaper — GPT-5.1 Codex High or GPT-6.1 Sol?
Which has a larger context window — GPT-5.1 Codex High or GPT-6.1 Sol?
The GPT-5.1 Codex High and GPT-6.1 Sol comparison is updated for 2026. Data includes benchmark results, API pricing, context window size and other specifications. For more detailed information, visit the GPT-5.1 Codex High or GPT-6.1 Sol page. See also the complete list of AI model comparisons.