OpenAI says GPT-6 Sol and Luna cost 50 percent less than GPT-5.6 promotional pricing, and credits caching and inference improvements.
openai.com, quoted / Introducing GPT-6 Sol and Luna · source · Quoted under the quotation exception; no licence granted
OpenAI: “GPT-5.6 Sol → GPT-6 Sol: $4 → $2 input, $20 → $10 output. Prices are per 1 million tokens. ...…” · openai.com, quoted / Introducing GPT-6 Sol and LunaClose
Key points
GPT-6 Sol costs $2 per million input tokens and $10 per million output tokens, down from $4 and $20.
GPT-6 Luna costs $0.10 per million input tokens and $0.50 per million output tokens, down from GPT-5.6 promotional prices of $0.20 and $1.20.
OpenAI calls this a 50 percent cut compared with GPT-5.6 promotional pricing and says caching and inference improvements paid for it.
What it means for you analysis
The 50 percent figure is OpenAI's own, and it is measured against GPT-5.6 promotional prices, so your saving depends on what you actually paid. Sol falls by exactly half on input and output, while Luna output falls by more than half, from $1.20 to $0.50. OpenAI says both models were trained with methods similar to GPT-6 Astra, but the claims we checked do not compare quality, and the page does not state how long these prices apply. Before moving a workload, set your last GPT-5.6 invoice beside these prices, test quality on your own tasks, and ask whether the new prices are fixed for a stated period.
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What this rests on
GPT-6 Sol is priced at $2 per million input tokens and $10 per million output tokens, down from $4 and $20, which OpenAI calls a 50 percent cut compared with GPT-5.6 promotional pricing.
narrowed to what the source supports Introducing GPT-6 Sol and Luna · OpenAI · 2026-09-22
reducing API prices for Sol and Luna by 50% compared with their GPT-5.6 promotional pricing
GPT-6 Luna is priced at $0.10 per million input tokens and $0.50 per million output tokens, down from GPT-5.6 promotional prices of $0.20 and $1.20.
narrowed to what the source supports Introducing GPT-6 Sol and Luna · OpenAI · 2026-09-22
reducing API prices for Sol and Luna by 50% compared with their GPT-5.6 promotional pricing
OpenAI says the models were trained with similar methods to GPT-6 Astra, introduced earlier the same month, and that caching and inference gains funded the price cut.
Introducing GPT-6 Sol and Luna · OpenAI · 2026-09-22
reducing API prices for Sol and Luna by 50% compared with their GPT-5.6 promotional pricing
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