GPT-5.6 Luna is the fast, cost-efficient model in OpenAI's GPT-5.6 series. It is suited for high-volume chat, classification, lightweight agentic workflows, and latency-sensitive reasoning tasks.
Added Jul 9, 2026
Context Window
1.1M
Max Output
128.0K
Avg output tokens (7d)
308 tokens
Input Price (Auto)
$0.20/1M
Output Price (Auto)
$1.20/1M
Cache Read (Auto)
$0.020/1M
Capabilities
Benchmarks
Benchmarks
Performance metrics and benchmarks
Sourced from Artificial Analysis.
Intelligence Index
37.3
Coding Index
71.4
Agentic Index
42.1
Agentic work
AutomationBench-AA
Workflow automation with guardrail penalties
50.2%
Better than 67% of models compared
Harvey LAB-AA
Legal agentic work criterion pass rate
87.9%
Better than 49% of models compared
AA-Briefcase
Agentic knowledge work (Elo)
1344 Elo
Better than 74% of models compared
GDPval-AA v2
Economically valuable tasks (Elo)
1463 Elo
Better than 82% of models compared
Document reasoning
GDP.pdf
Professional PDF reasoning: all-pass rate
24.0%
Better than 82% of models compared
AA-LCR v1.1
Long context reasoning with updated grading
83.7%
Better than 97% of models compared
MLCR-AA
Medical long-context reasoning
19.4%
Better than 65% of models compared
Reasoning
HLE
Humanity's Last Exam
39.5%
Better than 87% of models compared
CritPt
Research-level physics reasoning
20.6%
Coding
Terminal-Bench v4.0
Practical coding and terminal tasks
11.6%
Better than 64% of models compared
SciCode
Python programming for scientific computing
53.6%
Better than 69% of models compared
Knowledge
AA-Omniscience Accuracy
Proportion of correctly answered questions
42.7%
AA-Omniscience Hallucination Rate
Rate of incorrect answers among non-correct responses
92.6%
Legacy benchmarks
GPQA Diamond (legacy)
Graduate-level scientific reasoning
91.1%
Better than 91% of models compared
AA-LCR (unversioned / legacy)
Long context reasoning evaluation
83.7%
Better than 97% of models compared
GDPval-AA (unversioned / legacy)
Economically valuable tasks
48.2%
Last updated Oct 2, 2026
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openai/gpt-luna-latestCompatibility alias that routes to GPT 5.6 Luna, the latest supported GPT Luna model.
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openai/gpt-astra-latestCompatibility alias that routes to GPT 6 Astra, the latest supported GPT Astra model.
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