Model · OpenAI · Text
GPT-5.6 Luna
The cost-efficient tier of OpenAI's GPT-5.6 family — optimized for cost-sensitive, high-volume workloads. Keeps the family's 1.05M-token context window at the lowest price of the three tiers.
- Modality
- Text
- License
- Proprietary (Proprietary)
- Context window
- 1,050,000 tokens
- Released
- July 9, 2026
- Last verified
- July 10, 2026
- Runs locally
- No
- Also handles
- vision
Strengths
- Cheapest GPT-5.6 tier ($1 input / $6 output per MTok) — built for high-volume workloads
- 1.05M-token context window (128k max output) despite the low price
- February 2026 knowledge cutoff
- Vision-enabled; supports function calling, web search, file search, and computer use
Weaknesses
- Closed weights — API/product only
- Lowest-capability tier of the GPT-5.6 family — Sol or Terra for harder reasoning
Try it
| Where | Type | Notes |
|---|---|---|
| OpenAI API | hosted-api | API key required |
Version history
- GPT-5.6 Luna Jul 2026 Current
- GPT-5.6 Sol Jul 2026
- GPT-5.6 Terra Jul 2026
- GPT-5.5 Apr 2026
- GPT-5.4 mini Mar 2026
Official sources
- Model docs docs
- API changelog (release note) announcement
Change log
- — Initial entry. GPT-5.6 family released 2026-07-09 per OpenAI's API changelog; specs and pricing verified against the gpt-5.6-luna model docs.
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