GPT 5.1 Codex

Release Date: Nov 13, 2025

Developer OpenAI 🇺🇸

Context Window 400k

Max Output Tokens 128k

Token Costs (in/out) $1.25/10.00

Weights Private

Input Modalities

Accuracy

34.11 %

Avg. Cost (In/Out)

$ 1.25 / $ 10.00

Latency

30 min 29 s

BenchmarksAccuracyRankings

0.0%

±3.16

67/86

0.0%

±3.35

52/62

0.0%

±1.00

29/140

Proprietary BenchmarksAcademic BenchmarksIndustry Partners

View Hyperparameter Settings

Default Provider : OpenAI

Temperature: Default

Top P: Default

Top K: Default

Max Output Tokens: 128,000

Reasoning Effort: high