GPT-5.6 Luna
Last verified August 17, 2026 · OpenAI pricing ↗$0.200/1M input · $1.20/1M output · 1.1M context · OpenAI
GPT-5.6 Luna costs $0.200 per 1M input tokens and $1.20 per 1M output tokens from OpenAI, with a 1.1M-token context window. A typical chat reply (1,500 tokens in, 400 out) costs $0.0008, or $7.80 per 10,000 requests. On that workload it is cheaper than 130 of the 174 other buyable models tracked here.
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What GPT-5.6 Luna Costs Per Request
At $0.200 per 1M input and $1.20 per 1M output tokens, before caching or batch discounts.
| Workload | Input / output tokens | Per request | Per 10,000 requests |
|---|---|---|---|
| Chat reply | 1,500 / 400 | $0.0008 | $7.80 |
| RAG answer over retrieved docs | 8,000 / 600 | $0.0023 | $23.20 |
| Coding-agent step | 30,000 / 2,000 | $0.0084 | $84.00 |
GPT-5.6 Luna vs Similarly Priced Models
Nearest buyable models by price, with the RAG answer above (8,000 in / 600 out) priced on each.
| Model | Input /1M | Output /1M | Context | RAG answer |
|---|---|---|---|---|
| GPT-5.6 Luna OpenAI | $0.200 | $1.20 | 1.1M | $0.0023 |
| GPT-5.4 Nano OpenAI | $0.200 | $1.25 | 400K | $0.0024 |
| Qwen3-Next-80B-A3B-Thinking Alibaba | $0.150 | $1.20 | 262K | $0.0019 |
| Step 3.7 Flash StepFun | $0.200 | $1.15 | 262K | $0.0023 |
Alternatives to GPT-5.6 Luna
Pricing Details
OpenAI12H CACHE (2026-10-20): Responses API prompt_cache_options.ttl "12h" bills cache writes at 2.5x input, $0.50 per 1M (the default "30m" stays 1.25x); reads unchanged. Cheapest, fastest tier of the GPT-5.6 family, for routine latency- and cost-sensitive traffic. Price cut 80% on 2026-07-30 from $1.00/$6.00; every line fell by exactly 5x. Cached input: $0.02/1M. Batch and Flex: $0.10/$0.60. Fast mode (Priority Processing renamed 2026-07-30; both service_tier values still work): $0.40 input / $0.04 cached / $2.40 output, a flat 2x. Carries the highest published latency floor in the family, 99% of requests above 100 output tok/s, against Sol Fast's 80 despite costing 25x less on output. Above 272K input tokens the whole request bills at 2x input / 1.5x output ($0.40/$1.80). CHANGED 2026-08-05: Fast mode now accepts long-context prompts, and the pricing page publishes Fast long context at $0.80 input / $0.08 cached / $3.60 output. Batch/Flex long context: $0.20/$0.90. Now lists below OpenAI's own GPT-5.4 Nano ($0.20/$1.25). Knowledge cutoff Feb 16, 2026. Chat Completions and Batch only; no realtime, fine-tuning or embeddings. Artificial Analysis (max reasoning effort): Intelligence Index 51, 130M output tokens and $190.87 to run the index, 184.4 tok/s, 116.50s TTFT. Rates confirmed on OpenAI's own pricing page (verified 2026-07-31).
Input / 1M tokens
$0.2
Output / 1M tokens
$1.2
Context Window
1.1M
Max Output
128K
Price History
No price change recorded since 2026-08-09, when this site started tracking this model; it launched on 2026-06-26.
Frequently Asked Questions
Common questions about GPT-5.6 Luna pricing and usage
How much does GPT-5.6 Luna cost?
GPT-5.6 Luna costs $0.2 per 1 million input tokens and $1.2 per 1 million output tokens. This pricing is set by OpenAI.
What tokenizer does GPT-5.6 Luna use?
GPT-5.6 Luna uses the o200k_base tokenizer. This is OpenAI's latest tokenizer, optimized for efficiency with a vocabulary of ~200,000 tokens.
What is GPT-5.6 Luna's context window?
GPT-5.6 Luna supports a context window of 1.1M tokens (1,050,000 tokens). The maximum output length is 128K tokens.
How does GPT-5.6 Luna compare to other models?
On an 8,000-token-in, 600-token-out RAG answer, GPT-5.6 Luna costs $0.0023 per request. The nearest-priced alternatives cost: GPT-5.4 Nano (OpenAI) $0.0024, Qwen3-Next-80B-A3B-Thinking (Alibaba) $0.0019, Step 3.7 Flash (StepFun) $0.0023. The table above lists their full rates and context windows.
How do I count tokens for GPT-5.6 Luna?
Use the token counter at the top of this page or visit the homepage calculator. Paste your text and it will show the exact token count and cost for GPT-5.6 Luna using the o200k_base tokenizer.
Read More About GPT-5.6 Luna
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