In short
- GPT-6 Sol costs $2 per million input tokens and $10 per million output tokens, down from GPT-5.6 Sol's promotional prices of $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 · our view
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.
How we checked this · the sources3 checked facts from 1 source.
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Introducing GPT-6 Sol and Luna · OpenAI · archived copy
- 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.
Toned downchecked 28 Sep 2026GPT-5.6 Sol → GPT-6 Sol: $4 → $2 input, $20 → $10 output. Prices are per 1 million tokens. ... 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.
Toned downchecked 28 Sep 2026GPT-5.6 Luna → GPT-6 Luna: $0.20 → $0.10 input, $1.20 → $0.50 output. Prices are per 1 million tokens.
- 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.
checked 28 Sep 2026Earlier this month, we introduced GPT-6 Astra ... We trained GPT-6 Sol and Luna with similar methods as GPT-6 Astra ... Improvements in caching and inference let us serve these models at lower cost, and we’re passing those savings directly on to users and customers
- 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.
Corrections and updates
3 Oct 2026 · Correction: The first key point said GPT-6 Sol was down from $4 and $20. Those were GPT-5.6 Sol's promotional prices, not an earlier GPT-6 Sol price. It now says so.
Was: GPT-6 Sol costs $2 per million input tokens and $10 per million output tokens, down from $4 and $20.