OpenAI
GPT-5.6 Luna
GPT-5.6 Luna is a fast, cost-efficient model in OpenAI's GPT-5.6 series.
At a glance
- Input / 1M
- $0.20
- Output / 1M
- $1.20
- Context
- 1.05M
- Max output
- 128K
- Intelligence
- 37.3
- Released
- Jul 2026
Pricing
GPT-5.6 Luna API pricing
Per-token rates, plus what common tasks actually cost.
| Input tokensPer 1M tokens | $0.20 |
|---|---|
| Output tokensPer 1M tokens | $1.20 |
| Cached input (read)Per 1M tokens | $0.02 |
| Cache writePer 1M tokens | $0.25 |
| Long-context pricingPrompts above 272K tokens | $0.40 in / $1.80 out |
| Web searchPer request | $0.01 |
Chat message
2K in, 500 out
$1
per 1,000 requests
Coding task
30K in, 4K out
$10.80
per 1,000 requests
Long document summary
150K in, 2K out
$32.40
per 1,000 requests
Benchmarks
GPT-5.6 Luna benchmark scores
Independent scores from Artificial Analysis. Higher is better.
Intelligence index
37.3
Coding index
71.4
Agentic index
42.1
Specs
Context window and capabilities
What it can read, what it can write, and which API features it supports.
- Context window
- 1.05M tokens
- Max output
- 128K tokens
- Input types
- File, Image, Text
- Output types
- Text
- Reasoning effort
- Max, Extra high, High, Medium, Low, None
- Release date
- July 9, 2026
- Knowledge cutoff
- February 16, 2026
- Tool calling
- Structured outputs
- JSON mode
- Reasoning
- Temperature
- Stop sequences
- Deterministic seed
- Verbosity control
Compare
GPT-5.6 Luna vs other models
See how GPT-5.6 Luna stacks up head to head on price, benchmarks, and features.
VS
GPT-5.6 Luna vs DeepSeek V4.1 Flash
OpenAI vs DeepSeek
See comparisonVSGPT-5.6 Luna vs GLM 5.3 Flash
OpenAI vs Z.ai
See comparisonVSGPT-5.6 Luna vs MiMo-V2.6-Flash
OpenAI vs Xiaomi
See comparisonVSGPT-5.6 Luna vs Hy4 preview
OpenAI vs Tencent
See comparisonVSGPT-5.6 Luna vs GPT-6 Luna
OpenAI vs OpenAI
See comparisonVSGPT-5.6 Luna vs DeepSeek V4 Flash 0731
OpenAI vs DeepSeek
See comparisonMore GPT-5.6 Luna comparisons
- GPT-5.6 Luna vs Gemini 3.8 Flash
- GPT-5.6 Luna vs DeepSeek V4 Pro 0813
- GPT-5.6 Luna vs Claude Haiku 5.5
- GPT-5.6 Luna vs GPT-6 Luna Pro
- GPT-5.6 Luna vs Qwen3.8 27B
- GPT-5.6 Luna vs Gemini 3.7 Flash
- GPT-5.6 Luna vs Muse Spark 1.2
- GPT-5.6 Luna vs GPT-5.5
- GPT-5.6 Luna vs DeepSeek V4 Flash Vision Exp
- GPT-5.6 Luna vs Muse Spark 1.1
- GPT-5.6 Luna vs GLM 5.3 FlashX
- GPT-5.6 Luna vs GPT-5.6 Luna Pro
Alternatives
GPT-5.6 Luna alternatives
Similar models worth considering, and where each one has the edge.
Z.ai
GLM 5.3 Flash
Gemini 3.8 Flash
Gemini 3.7 Flash
Want to learn about other models? Browse all models
FAQ
Frequently asked questions
How much does GPT-5.6 Luna cost?
GPT-5.6 Luna costs $0.20 per 1M input tokens and $1.20 per 1M output tokens through the API. A typical chat message costs about $1 per 1,000 messages.
What is the context window of GPT-5.6 Luna?
GPT-5.6 Luna accepts up to 1.05M tokens of input and can write up to 128K tokens in a single response.
What is the best alternative to GPT-5.6 Luna?
GLM 5.3 Flash from Z.ai is a strong alternative. It offers: 2.4x cheaper output, higher intelligence score, accepts video.
Can I use GPT-5.6 Luna alongside other models?
Yes. Shortcut Chat sends one prompt to GPT-5.6 Luna and any other models you pick at the same time, so you can compare answers side by side.
Try GPT-5.6 Luna next to every other model.
Use GPT-5.6 Luna alongside all the other models. Use one at a time, or multiple together. Get the best answer from every AI.