AI model comparison
Hy4 vs GPT-5.6 Luna
Side by side comparison of Hy4 and GPT-5.6 Luna on pricing, benchmark scores, context window, and more.
The official release of Hy4 delivers comprehensive and substantial improvements over Hy4 Preview, with particularly strong gains in agentic capabilities and performance across a wide range of long-horizon, real-world productivity
- Input / 1M
- $0.42
- Output / 1M
- $1.25
- Context
- 1.05M
GPT-5.6 Luna is a fast, cost-efficient model in OpenAI's GPT-5.6 series.
- Input / 1M
- $0.20
- Output / 1M
- $1.20
- Context
- 1.05M
Comparing image generators? Compare image models
At a glance
Quick verdict
How the two models stack up on the things people ask about most.
Lower price
GPT-5.6 Luna
1.5x cheaper for a typical chat
Higher intelligence score
Not available
Not enough benchmark data
Larger context window
GPT-5.6 Luna
1.05M vs 1.05M tokens
Newer release
Hy4
Released November 4, 2026
Benchmarks
Benchmark scores
Independent scores from Artificial Analysis. Higher is better.
Intelligence index
GPT-5.6 LunaNot availableCoding index
GPT-5.6 Luna71.4Agentic index
GPT-5.6 Luna42.1Pricing
Hy4 vs GPT-5.6 Luna API pricing
Per-token API rates. Cheaper option highlighted.
| Metric | GPT-5.6 Luna | |
|---|---|---|
| Input tokensPer 1M tokens | $0.42 | $0.20 |
| Output tokensPer 1M tokens | $1.25 | $1.20 |
| Cached input (read)Per 1M tokens | $0.02 | $0.02 |
| Cache writePer 1M tokens | Not available | $0.25 |
| Long-context pricingPer 1M tokens, for very long prompts | Same rate at any length | $0.40 in / $1.80 out above 272K |
| Web searchPer request | Not available | $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$1Coding task
30K in, 4K out
GPT-5.6 Luna$10.80$5.40 cachedLong document summary
150K in, 2K out
GPT-5.6 Luna$32.40$5.40 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 | |
|---|---|---|
| Context window | 1.05M tokens | 1.05M tokens |
| Max output | 66K tokens | 128K tokens |
| Input types | Image, Text | File, Image, Text |
| Output types | Text | Text |
| Reasoning effort levels | High, Low, None | Max, Extra high, High, Medium, Low, None |
| Default reasoning effort | High | Medium |
| Release date | November 4, 2026 | July 9, 2026 |
Features
Supported features
API features available for each model.
| Metric | GPT-5.6 Luna | |
|---|---|---|
| Tool calling | Supported | Supported |
| Structured outputs | Supported | Supported |
| JSON mode | Supported | Supported |
| Reasoning | Supported | Supported |
| Temperature | Supported | Not supported |
| Stop sequences | Supported | Not supported |
| Deterministic seed | Not supported | Supported |
| Verbosity control | Not 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 LunaView full model details- GPT-5.6 Luna vs DeepSeek V4.1 Flash 1017
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- GPT-5.6 Luna vs GLM 5.3 Flash
- GPT-5.6 Luna vs GPT-6 Luna
- GPT-5.6 Luna vs Claude Opus 5.5
- GPT-5.6 Luna vs Step 5 Preview
- GPT-5.6 Luna vs MiniMax M3.1 Flash
- GPT-5.6 Luna vs GPT-6.1 Sol
- GPT-5.6 Luna vs DeepSeek V4 Flash 0731
- GPT-5.6 Luna vs GLM 5.3
- GPT-5.6 Luna vs Hy3
- GPT-5.6 Luna vs GPT-6.1 Terra
- GPT-5.6 Luna vs GPT-6 Luna Pro
- GPT-5.6 Luna vs DeepSeek V4 Pro 0423
- GPT-5.6 Luna vs Gemini 3.1 Flash Lite
- GPT-5.6 Luna vs MiniMax M3
- GPT-5.6 Luna vs Step 3.7 Flash
- GPT-5.6 Luna vs gpt-oss-120b
- GPT-5.6 Luna vs Gemini 2.5 Flash
- GPT-5.6 Luna vs GPT-4o-mini
- GPT-5.6 Luna vs Qwen3.6 35B A3B
- GPT-5.6 Luna vs GLM 5.3 FlashX
- GPT-5.6 Luna vs GPT-5.6 Luna Pro
- GPT-5.6 Luna vs Beam 1.0 501B A23B
- GPT-5.6 Luna vs MiMo-V2.5
- GPT-5.6 Luna vs Muse Glimmer 30B
- GPT-5.6 Luna vs MiMo-V2.5-Pro
- GPT-5.6 Luna vs Mistral Small 4
- GPT-5.6 Luna vs Inkling Small
- GPT-5.6 Luna vs Command A+
Our take
GPT-5.6 Luna is 1.5x cheaper for a typical chat. GPT-5.6 Luna has the larger context window (1.05M vs 1.05M 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 Hy4 or GPT-5.6 Luna cheaper?
GPT-5.6 Luna is cheaper for a typical chat (2K input tokens and 500 output tokens). GPT-5.6 Luna costs $0.20 per 1M input tokens and $1.20 per 1M output tokens, while Hy4 costs $0.42 per 1M input tokens and $1.25 per 1M output tokens.
Which has a bigger context window, Hy4 or GPT-5.6 Luna?
GPT-5.6 Luna supports up to 1.05M tokens of context, compared with 1.05M for Hy4.
Can I use Hy4 and GPT-5.6 Luna at the same time?
Yes. Shortcut Chat sends one prompt to multiple models at once, so you can see Hy4 and GPT-5.6 Luna answer side by side and keep the better response.
Why choose? Ask both.
Send one prompt to Hy4 and GPT-5.6 Luna at the same time. Compare the answers side by side and keep the best one.