GPT-6 Luna API pricing — what it really costs
GPT-6 Luna (OpenAI) costs $0.100 per 1M input tokens and $0.500 per 1M output tokens — with prompt caching, cached input drops to $0.010. Prices verified 2026-10-17; we track the price you are actually billed today, including promotional rates.
Price per 1M tokens
| Input | Output | Cached input |
|---|---|---|
| $0.100 | $0.500 | $0.010 |
Real monthly costs on GPT-6 Luna
Three realistic workloads, computed from the prices above (cached share billed at the cache-read rate where the provider offers one):
Customer-support chatbot
$0.342/mo
2M input + 0.5M output tokens/month, 60% of input served from prompt cache
RAG / document Q&A
$1.24/mo
20M input + 1M output tokens/month, 70% cached (shared context)
Agentic coding assistant
$3.90/mo
50M input + 5M output tokens/month, 80% cached (long sessions)
Want exact numbers for your usage? Open the calculator — same verified prices, your token volumes.
Compare GPT-6 Luna
FAQ
How much does the GPT-6 Luna API cost?
GPT-6 Luna costs $0.100 per 1M input tokens and $0.500 per 1M output tokens. Cached input tokens cost $0.010 per 1M. Pricing verified 2026-10-17.
What does a typical workload cost on GPT-6 Luna?
Customer-support chatbot: about $0.342/month (2M input + 0.5M output tokens/month, 60% of input served from prompt cache). RAG / document Q&A: about $1.24/month (20M input + 1M output tokens/month, 70% cached (shared context)). Agentic coding assistant: about $3.90/month (50M input + 5M output tokens/month, 80% cached (long sessions))
Is GPT-6 Luna expensive compared to other models?
No — GPT-6 Luna is currently tied for the cheapest model in our comparison of 23 popular API models (with Claude Haiku 5.5).