Prices → GPT-5.6 Luna
GPT-5.6 Luna API pricing
GPT-5.6 Luna from OpenAI is priced at $0.100 per 1M input tokens and $0.600 per 1M output tokens, with a 400k-token context window. Output costs 6.0x what input costs, which is the number that decides whether this model is expensive for you.
What GPT-5.6 Luna costs on real workloads
Monthly cost at each workload's default volume, shown with and without prompt caching. The right-hand column is what caching is worth on this specific model.
| Workload | Calls/mo | No cache | With cache | Saved |
|---|---|---|---|---|
| Customer support chatbot | 50,000 | $19.50 | $14.64 | 25% |
| RAG document Q&A | 20,000 | $23.20 | $19.60 | 16% |
| Coding agent | 4,000 | $17.20 | $10.45 | 39% |
| Bulk summarization | 100,000 | $144.00 | $138.60 | 4% |
| Structured data extraction | 500,000 | $250.00 | $187.00 | 25% |
| Long-form content generation | 10,000 | $26.00 | $25.46 | 2% |
| Email triage agent | 200,000 | $68.00 | $43.25 | 36% |
| Translation pipeline | 150,000 | $166.50 | $164.47 | 1% |
On caching
Cached input reads at $0.010 per 1M, a 90% discount on fresh input. On a workload that re-sends the same system prompt or the same documents every call, that discount is usually the single largest lever available — larger than switching models.
Closest alternatives by price
The six models nearest GPT-5.6 Luna on blended rate — the realistic swap candidates.
| Model | In /1M | Out /1M | Blended | vs GPT-5.6 Luna | |
|---|---|---|---|---|---|
| Gemini 2.5 Flash-Lite | $0.100 | $0.400 | $0.175 | -22% | compare |
| Gemini 3.1 Flash-Lite | $0.250 | $1.500 | $0.562 | +150% | — |
| Gemini 3.5 Flash-Lite | $0.300 | $2.500 | $0.850 | +278% | — |
| Gemini 2.5 Flash | $0.300 | $2.500 | $0.850 | +278% | — |
| Gemini 3.7 Flash | $0.750 | $3.750 | $1.500 | +567% | compare |
| Gemini 3.6 Flash | $0.750 | $3.750 | $1.500 | +567% | — |
Price it against your own volume
Cost calculator
Enter your own numbers, or start from a workload preset. Costs are monthly and update as you type.
| Model | In /1M | Out /1M | Monthly | vs best |
|---|
Cutting this bill in practice
If a cheaper model on the table above would work for your task, the blocker is usually integration effort rather than the price difference.
Switch models without rewriting your integration
The savings on this page are only real if you can actually move traffic to the cheaper model. Aggregators and gateways sit in front of multiple providers so that switch is a configuration change.
- AIML API
One API surface in front of 200+ models. The reason it matters for cost: switching model becomes a string change rather than an integration rewrite, so the savings this site calculates are actually reachable instead of theoretical.
Caveat: Adds a middleman margin on top of provider rates — check its per-model pricing against the tables above before assuming it is cheaper. - OpenRouter
Provider-agnostic routing with automatic fallback. Useful when the cheapest model for a workload changes month to month — which, given how often the tables on this site move, it does.
Caveat: Routing does not make any individual model cheaper. It reduces the cost of switching, not the token price.