GPT-5.6 Luna is $1.8 cheaper per 1M input tokens (90% lower; 10x difference).
API cost decision in 10 seconds
🔥GPT-5.6 Luna vs 🔥Claude Sonnet 5
Pick GPT-5.6 Luna when budget and context both matter.
Page updated:
Data confirmed:
Prices normalized to USD per 1M tokens
Sample workload: 1M input + 500K output
Budget verdict
Pick GPT-5.6 Luna when budget and context both matter.
On the standard 1M input plus 500K output workload, GPT-5.6 Luna is estimated at $0.8 vs $7 for Claude Sonnet 5, saving $6.2 (88.6% lower).
Cost-first pickGPT-5.6 Luna
Context-first pickGPT-5.6 Luna
Sample savings$6.288.6%
10x traffic gap$62
GPT-5.6 Luna is cheaper on the standard workload and also has the larger context window. At 10x that traffic, the same price gap is about $62. Use the calculator below to replace the sample workload with your own token volume.
Cost sensitivity
Workload Sensitivity
GPT-5.6 Luna stays cheaper across input-heavy, balanced, and output-heavy sample workloads.
| Workload shape | Token mix | Better pick | GPT-5.6 Luna | Claude Sonnet 5 |
|---|---|---|---|---|
| Input-heavy / RAG | 5M input + 500K output | GPT-5.6 Luna | $1.6 | $15 |
| Balanced workload | 1M input + 1M output | GPT-5.6 Luna | $1.4 | $12 |
| Output-heavy chatbot | 1M input + 5M output | GPT-5.6 Luna | $6.2 | $52 |
GPT-5.6 Luna is $8.8 cheaper per 1M output tokens (88% lower; 8.33x difference).
GPT-5.6 Luna has 50K more context (1.05x larger).
GPT-5.6 Luna is $6.2 cheaper on the standard workload (88.6% lower).
Estimate your workload cost
Your Workload Cost
This estimate uses normalized public API pricing per 1M tokens. It is a planning aid, not a billing quote. Verify provider pricing, limits, and terms before production use.
Quick Decision
GPT-5.6 Luna has the lower input price; GPT-5.6 Luna has the lower output price; GPT-5.6 Luna offers the larger context window. For the 1M input plus 500K output sample, GPT-5.6 Luna is cheaper for the standard workload.
For a 1M input token plus 500K output token workload, the estimated API cost is $0.8 for GPT-5.6 Luna and $7 for Claude Sonnet 5.
Choose GPT-5.6 Luna when you care most about lower input-token price, lower output-token price, and larger context window.
Choose Claude Sonnet 5 when its provider, model quality, latency, or availability is more important than the numeric price/context winner.
- On the standard 1M input plus 500K output workload, GPT-5.6 Luna is estimated at $0.8 vs $7 for Claude Sonnet 5, saving $6.2 (88.6% lower).
- GPT-5.6 Luna is $6.2 cheaper on the standard workload (88.6% lower).
- GPT-5.6 Luna is $1.8 cheaper per 1M input tokens (90% lower; 10x difference).
- GPT-5.6 Luna is $8.8 cheaper per 1M output tokens (88% lower; 8.33x difference).
- GPT-5.6 Luna has 50K more context (1.05x larger).
| Feature | 🔥GPT-5.6 Luna (OpenAI) | 🔥Claude Sonnet 5 (Anthropic) |
|---|---|---|
| Input Price prompt tokens per 1M | $0.2 | $2 |
| Completion Price per 1M tokens | $1.2 | $10 |
| Sample Workload Cost 1M input + 500K output | $0.8 | $7 |
| Context Window | 1.05M | 1M |
| Release Date | ||
| Popularity | #6 | #16 |
Use-Case Decision Matrix
| Use case | Better pick | Why |
|---|---|---|
| Budget-constrained production | GPT-5.6 Luna | On the standard 1M input plus 500K output workload, GPT-5.6 Luna is estimated at $0.8 vs $7 for Claude Sonnet 5, saving $6.2 (88.6% lower). |
| High-volume input processing | GPT-5.6 Luna | Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill. |
| Long responses and chatbots | GPT-5.6 Luna | Lower output-token price matters most when assistants generate many completion tokens. |
| RAG or long-document work | GPT-5.6 Luna | A larger context window leaves more room for retrieved passages, conversation history, or source files. |
Related Alternatives
- gpt-oss-120b (free) can replace GPT-5.6 Luna when lower sample workload cost matters most: $0.
- gpt-oss-20b (free) can replace GPT-5.6 Luna when lower sample workload cost matters most: $0.
- gpt-oss-20b can replace GPT-5.6 Luna when lower sample workload cost matters most: $0.1.
- gpt-oss-120b can replace GPT-5.6 Luna when lower sample workload cost matters most: $0.12.
- Grok 4.20 Multi-Agent offers 2M context with $2.5 sample workload cost.
- Grok 4.20 offers 2M context with $2.5 sample workload cost.
- DeepSeek V4 Flash 0731 offers 1.31M context with $0.17 sample workload cost.
- DeepSeek V4 Flash Latest offers 1.31M context with $0.11 sample workload cost.
- DeepSeek V4 Flash 0731 · DeepSeek · #1
- MiMo-V2.5 · Xiaomi · #2
- Hy3 · Tencent · #3
- Ox Alpha · stealth · #4
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