GPT-5.1
GPT-5.1 is an API-only (closed weights) language model from OpenAI, released November 13, 2025. The context window is 391K tokens. On the Epoch Capabilities Index it scores 150.9, rank 65 of 256 rated models. API price: $1.25 input / $10 output per million tokens.
"Today we’re upgrading the GPT‑5 series with the release of: GPT‑5.1 Instant: our most-used model, now warmer, more intelligent, and better at following your instructions. GPT‑5.1 Thinking: our advanced reasoning model, now easier to understand and faster on simple tasks, more persistent on complex ones.
Check it against your own PC →
Strengths by category
ModelTape's 0–100 fit on Epoch AI benchmark results.
| Category | Score | Based on |
|---|---|---|
| Reasoning | 17.2 | Chess Puzzles, SimpleBench, Mystery Game Puzzles, Humanity's Last Exam |
| Math | 67.5 | OTIS Mock AIME 2024-2025, FrontierMath-2025-02-28-Private, FrontierMath-Tier-4-2025-07-01-Private |
| Coding | 43.9 | GSO-Bench, Terminal Bench, SWE-bench Verified |
| Knowledge | 74.0 | GPQA diamond, SimpleQA Verified |
Benchmark results
| Benchmark (Epoch AI) | Score |
|---|---|
| OTIS Mock AIME | 88.6% |
| GPQA Diamond | 87.0% |
| SWE-bench Verified | 68.0% |
| FrontierMath-2025-02-28-Private | 54.4% |
| SimpleQA Verified | 48.0% |
| Terminal-Bench | 47.6% |
| SimpleBench | 43.8% |
| Chess Puzzles | 39.0% |
| Humanity's Last Exam | 23.7% |
| FrontierMath-Tier-4-2025-07-01-Private | 20.8% |
| GSO-Bench | 13.7% |
| Mystery Game Puzzles | 10.8% |
Links
Announcement · Epoch AI benchmarks
Models with a similar score
Muse Spark 1.1 · Mistral Large 4 · Qwen3.7-Max · GPT-5.2 · DeepSeek V4 Flash 0731 · GLM-5.3-Flash · Muse Spark · GLM-5.2
More from OpenAI
GPT-6.1 Terra · GPT-6.1 Sol · GPT-6 Sol · GPT-6 Luna · GPT-6 Astra · GPT-5.6 Cyber · Daybreak Red · Daybreak Blue