About
GPT-5.1-Codex is a specialized version of GPT-5.1 optimized for software engineering and coding workflows. It is designed for both interactive development sessions and long, independent execution of complex engineering tasks....
Related Models
Pricing
Input
$1.25
per 1M tokens
Output
$10.00
per 1M tokens
Blended
$3.44
per 1M tokens
Cheaper than 18% of models. Median price is $0.54/1M tokens.
Cost Calculator
Tokens per day1M
100K100M
Daily
$3.44
Monthly
$103.13
vs. Similar Models
Anthropic: Claude Opus 4.5Q:0.0
$10.00+191%
Claude 4.5 Sonnet (Reasoning)Q:0.0
$6.00+75%
KAT-Coder-Pro V1Q:-0.1
$0.53-85%
Kimi K2.6 (Non-reasoning)Q:-0.1
$1.71-50%
Performance
206
tokens/sec
Faster than 88% of models
2.77
seconds
Faster than 20% of models
2.77
seconds
Faster than 50% of models
Market Median
94 tok/s
118% faster
Median TTFT
1.11s
149% slower
Throughput/Dollar
60
tok/s per $/1M
Speed Comparison
Gemini 3.5 Flash (minimal)
203 tok/s-1%
Grok 4.20 0309 v2 (Non-reasoning)
201 tok/s-2%
Google: Gemini 3.5 Flash
210 tok/s+2%
Context Window
400K
tokens
Larger than 76% of models
Max Output
128K
tokens
32% of context
Benchmarks
MMLU-Pro
86.0%
GPQA Diamond
86.0%
HLE
23.4%
LiveCodeBench
84.9%
SciCode
40.2%
TerminalBench Hard
34.8%
MATH-500Not evaluated
AIMENot evaluated
AIME 2025
95.7%
IFBench
70.0%
Long Context Recall
67.3%
Tau2
83.0%
Market AverageTop Score