AI model comparison
GPT-5.6 Luna Pro vs GPT-5.4 Nano
Pricing, context window, benchmarks, and features compared side by side. Or skip the guesswork and send one prompt to both.
OpenAI
GPT-5.6 Luna Pro
GPT-5.6 Luna Pro is the same underlying model as [GPT-5.6 Luna](https://openrouter.ai/openai/gpt-5.6-luna), served with `reasoning.mode` set to `pro` for higher-quality responses on complex tasks.
- Input / 1M
- $0.20
- Output / 1M
- $1.20
- Context
- 1.05M
OpenAI
GPT-5.4 Nano
GPT-5.4 nano is the most lightweight and cost-efficient variant of the GPT-5.4 family, optimized for speed-critical and high-volume tasks.
- Input / 1M
- $0.20
- Output / 1M
- $1.25
- Context
- 400K
At a glance
Quick verdict
How the two models stack up on the things people ask about most.
Lower price
GPT-5.6 Luna Pro
1.0x cheaper for a typical chat
Higher intelligence score
Tie
Not enough benchmark data
Larger context window
GPT-5.6 Luna Pro
1.05M vs 400K tokens
Newer release
GPT-5.6 Luna Pro
Released July 9, 2026
Benchmarks
Benchmark scores
Independent scores from Artificial Analysis. Higher is better.
Intelligence index
GPT-5.6 Luna ProNot availableGPT-5.4 Nano20.7Coding index
GPT-5.6 Luna ProNot availableGPT-5.4 Nano56.1Agentic index
GPT-5.6 Luna ProNot availableGPT-5.4 Nano16Pricing
GPT-5.6 Luna Pro vs GPT-5.4 Nano API pricing
Per-token API rates. Cheaper option highlighted.
| Metric | GPT-5.6 Luna Pro | GPT-5.4 Nano |
|---|---|---|
| Input tokensPer 1M tokens | $0.20 | $0.20 |
| Output tokensPer 1M tokens | $1.20 | $1.25 |
| Cached input (read)Per 1M tokens | $0.02 | $0.02 |
| Cache writePer 1M tokens | $0.25 | Not available |
| Long-context pricingPer 1M tokens, for very long prompts | $0.40 in / $1.80 out above 272K | Same rate at any length |
| Web searchPer request | $0.01 | $0.01 |
What it costs in practice
Estimated cost per 1,000 requests at standard rates. Coding and long-document figures also show the cost when the input is already cached.
Chat message
2K in, 500 out
GPT-5.6 Luna Pro$1GPT-5.4 Nano$1.02Coding task
30K in, 4K out
GPT-5.6 Luna Pro$10.80$5.40 cachedGPT-5.4 Nano$11$5.60 cachedLong document summary
150K in, 2K out
GPT-5.6 Luna Pro$32.40$5.40 cachedGPT-5.4 Nano$32.50$5.50 cachedSpecs
Context window and capabilities
How much each model can read, how much it can write, and what it accepts as input.
| Metric | GPT-5.6 Luna Pro | GPT-5.4 Nano |
|---|---|---|
| Context window | 1.05M tokens | 400K tokens |
| Max output | 128K tokens | 128K tokens |
| Input types | File, Image, Text | File, Image, Text |
| Output types | Text | Text |
| Reasoning effort levels | Max, Extra high, High, Medium, Low, None | Extra high, High, Medium, Low, None |
| Default reasoning effort | Medium | Medium |
| Release date | July 9, 2026 | March 17, 2026 |
Features
Supported features
API features available for each model.
| Metric | GPT-5.6 Luna Pro | GPT-5.4 Nano |
|---|---|---|
| Tool calling | Supported | Supported |
| Structured outputs | Supported | Supported |
| JSON mode | Supported | Supported |
| Reasoning | Supported | Supported |
| Temperature | Not supported | Not supported |
| Stop sequences | Not supported | Not supported |
| Deterministic seed | Supported | Supported |
| Verbosity control | Supported | Supported |
Keep exploring
More on these models
Other head-to-heads, the full model page, and the alternatives list for each model.
GPT-5.6 Luna ProView full model details- GPT-5.6 Luna Pro vs DeepSeek V4.1 Flash
- GPT-5.6 Luna Pro vs GLM 5.3 Flash
- GPT-5.6 Luna Pro vs Hy4 preview
- GPT-5.6 Luna Pro vs GPT-6 Luna
- GPT-5.6 Luna Pro vs DeepSeek V4 Flash 0731
- GPT-5.6 Luna Pro vs DeepSeek V4 Flash 0423
- GPT-5.6 Luna Pro vs GPT-5.6 Luna
- GPT-5.6 Luna Pro vs MiniMax M3
- GPT-5.6 Luna Pro vs GPT-4.1 Mini
GPT-5.4 NanoView full model details- GPT-5.4 Nano vs DeepSeek V4 Flash 0423
- GPT-5.4 Nano vs DeepSeek V3.2
- GPT-5.4 Nano vs Gemini 3.5 Flash Lite
- GPT-5.4 Nano vs Step 3.7 Flash
- GPT-5.4 Nano vs GPT-5 Mini
- GPT-5.4 Nano vs Qwen3.6 35B A3B
- GPT-5.4 Nano vs MiniMax M2.7
- GPT-5.4 Nano vs MiniMax M2.5
- GPT-5.4 Nano vs MiniMax M2.1
- GPT-5.4 Nano vs GPT-5.1-Codex-Mini
- GPT-5.4 Nano vs o3
- GPT-5.4 Nano vs Qwen3.5-35B-A3B
- GPT-5.4 Nano vs LongCat 2.0
- GPT-5.4 Nano vs MiniMax M2
- GPT-5.4 Nano vs Muse Glimmer 30B
Our take
GPT-5.6 Luna Pro is 1.0x cheaper for a typical chat. GPT-5.6 Luna Pro has the larger context window (1.05M vs 400K tokens). The right pick depends on your workload, so the quickest way to settle it is to send the same prompt to both and compare.
FAQ
Frequently asked questions
Is GPT-5.6 Luna Pro or GPT-5.4 Nano cheaper?
GPT-5.6 Luna Pro is cheaper for a typical chat (2K input tokens and 500 output tokens). GPT-5.6 Luna Pro costs $0.20 per 1M input tokens and $1.20 per 1M output tokens, while GPT-5.4 Nano costs $0.20 per 1M input tokens and $1.25 per 1M output tokens.
Which has a bigger context window, GPT-5.6 Luna Pro or GPT-5.4 Nano?
GPT-5.6 Luna Pro supports up to 1.05M tokens of context, compared with 400K for GPT-5.4 Nano.
Can I use GPT-5.6 Luna Pro and GPT-5.4 Nano at the same time?
Yes. Shortcut Chat sends one prompt to multiple models at once, so you can see GPT-5.6 Luna Pro and GPT-5.4 Nano answer side by side and keep the better response.
Why choose? Ask both.
Send one prompt to GPT-5.6 Luna Pro and GPT-5.4 Nano at the same time. Compare the answers side by side and keep the best one.