← API pricing · OpenAI
OpenAI API pricing
What each of OpenAI's 6 live models costs on OpenAI's own API, in US dollars per million tokens: input, output and input read from the prompt cache, plus the higher rate past each long-prompt threshold. These are the published list prices in the models.dev catalog as of October 25, 2026, refreshed daily. The AW Index column is each model's standing on the bench index.
| Model | Input | Output | Cached input | Context | AW Index |
|---|---|---|---|---|---|
GPT-6 AstraOpenAI · gpt-6-astra | $10† | $50† | $1 | 1.05M | 87.4 |
GPT-6.1 SolOpenAI · gpt-6.1-sol | $2† | $10† | $0.10 | 1.05M | 82.9 |
GPT-6 SolOpenAI · gpt-6-sol | $2† | $10† | $0.20 | 1.05M | 68.6 |
ChatGPT-5.6OpenAI · gpt-5.6 | $4† | $20† | $0.40 | 1.05M | 50 |
GPT-5.5OpenAI · gpt-5.5 | $5† | $30† | $0.50 | 1.05M | 42.6 |
GPT-6 LunaOpenAI · gpt-6-luna | $0.10† | $0.50† | $0.01 | 1.05M | 28 |
† Long prompts cost more: GPT-6 Astra $20 / $75 over 272K tokens; GPT-6.1 Sol $4 / $15 over 272K tokens; GPT-6 Sol $4 / $15 over 272K tokens; ChatGPT-5.6 $8 / $30 over 272K tokens; GPT-5.5 $10 / $45 over 272K tokens; GPT-6 Luna $0.20 / $0.75 over 272K tokens.
What a workload costs on these models, side by side: the cost calculator, filtered to OpenAI.
Quick answers
What is the cheapest OpenAI model on the API?
GPT-6 Luna, at $0.10 input / $0.50 output per million tokens, the lowest input and output price of OpenAI's 6 priced models.
What is OpenAI's most expensive model?
GPT-6 Astra, at $10 input / $50 output per million tokens.
Does OpenAI discount cached input?
Yes. Input read from the prompt cache costs 90% to 95% less than normal input across the 6 models that publish a cached price, from GPT-6.1 Sol (95% off) to GPT-6 Astra, GPT-6 Sol, ChatGPT-5.6, GPT-5.5 and GPT-6 Luna (90% off).
Does OpenAI charge more for long prompts?
On 6 of its 6 priced models: GPT-6 Astra goes to $20 / $75 past 272K tokens; GPT-6.1 Sol goes to $4 / $15 past 272K tokens; GPT-6 Sol goes to $4 / $15 past 272K tokens; ChatGPT-5.6 goes to $8 / $30 past 272K tokens; GPT-5.5 goes to $10 / $45 past 272K tokens; GPT-6 Luna goes to $0.20 / $0.75 past 272K tokens.
How do OpenAI's prices compare with other labs?
Its cheapest model by output price, GPT-6 Luna, ranks 4 of the 39 priced models from every lab on output price. Prices are OpenAI's own list prices from the models.dev catalog as of October 25, 2026; clouds and resellers may charge differently.
Other labs: Anthropic · Google · Meta · xAI · Zhipu AI · Alibaba · MiniMax · Moonshot · Xiaomi · every model in one table · prompt caching prices
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<a href="https://artificialwatch.com/llm-pricing/openai">OpenAI API pricing</a>ArtificialWatch, "OpenAI API pricing", https://artificialwatch.com/llm-pricing/openaiOpenAI ships often. Get an alert when its next model lands.
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