GPT-5.1 Codex Mini

by OpenAI

Fast, efficient code model via Azure OpenAI (EU region)

ToolsStructured output
Context window
272K
Max output
128K
Input price
$0.25 /1M
Output price
$2.00 /1M

Benchmarks

Independent benchmark scores — composite indices for reasoning, coding, and math, plus individual eval scores where available.

Global rank#85 of 505 LLMs
TierStrong
Output speed200 tok/s
First token3.31s
Intelligence Index38.6
Coding Index36.4
Math Index91.7
MMLU-Pro
82%
GPQA Diamond
81%
Humanity's Last Exam
17%
LiveCodeBench
84%
SciCode
43%
AIME 2025
92%
IFBench
68%
Long-context reasoning
63%
Terminal-Bench Hard
33%
τ²-Bench Telecom
63%

Available routes

The same GPT-5.1 Codex Mini runs on 2 different routes through the Opper gateway. Each route has its own data-handling posture.

ProviderRegionZero data retentionTrainingLoggingContractInputOutput
Azure OpenAIEUOpt-inNo
Up to 30 days for abuse monitoring
EA/MCA-E$0.25$2.00
OpenAIUSOpt-inNo (opt-in)
Up to 30 days for abuse monitoring on stateless endpoints. Stateful endpoints (Conversations, ChatKit, Vector Stores) retain until deleted.
Enterprise$0.25$2.00

Human review: Abuse-flagged only

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GPT-5.1 Codex Mini by OpenAI — pricing, benchmarks, hosting routes | Opper AI