GPT-5.6 Luna
OpenAI·
LLMssmallcloud
Overview
Lightweight, cost-efficient tier of OpenAI's GPT-5.6 Sol/Terra/Luna family, aimed at smaller and faster tasks. Lowest-cost option in the family at $1/M input, $6/M output tokens. Part of the limited preview from 2026-06-26; generally available 2026-07-09.
Capabilities and innovations
Agentic codingTool use / function callingProgrammatic tool calling (Responses API)Sol / Terra / Luna model family
Benchmarks
| Benchmark | Score | Source |
|---|---|---|
| Terminal-Bench 2.x | 84.3% | vendor Terminal-Bench 2.1: 84.3% (OpenAI self-report, Luna tier; exceeds Terra despite the lower tier positioning). |
- GPQA Diamond: independent evaluation pending
- Humanity’s Last Exam (no tools): independent evaluation pending
- SWE-bench Pro: independent evaluation pending
- MMLU-Pro: independent evaluation pending
- Terminal-Bench 3.0: independent evaluation pending
- MMMU-Pro: independent evaluation pending
Links
More from OpenAI
Data curated by AI Model Timeline. See the methodology for admission criteria, benchmark eras and source priority.