OpenAI just made its newest model family significantly cheaper, and it did so faster than almost anyone expected. Just three weeks after the general availability of GPT-5.6, the company is cutting prices for two of the family's three tiers, passing along efficiency gains it credits largely to GPT-5.6 Sol itself.
The numbers that matter
The cuts are not incremental. GPT-5.6 Luna, the fastest and lowest-cost tier, drops by roughly 80% -- it now costs $0.20 per million input tokens and $1.20 per million output tokens. That is a dramatic fall from its launch price of $1/$6. Terra, the mid-range tier, gets a 20% reduction, landing at $2 per million input tokens and $12 per million output tokens. The most powerful version, GPT-5.6 Sol, won't see a price cut.
Here is how the updated pricing stacks up against launch prices and the competition:
| Model | Input (old) | Input (new) | Output (old) | Output (new) |
|---|---|---|---|---|
| GPT-5.6 Luna | $1.00/M | $0.20/M | $6.00/M | $1.20/M |
| GPT-5.6 Terra | $2.50/M | $2.00/M | $15.00/M | $12.00/M |
| GPT-5.6 Sol | $5.00/M | $5.00/M | $30.00/M | $30.00/M |
A new gear for Sol
Sol is not getting cheaper, but it is getting faster. OpenAI is introducing a Fast mode for GPT-5.6 Sol in the API, which delivers up to 2.5x the speed of standard processing at 2x the standard price. The company says there is no change in intelligence -- you are paying for throughput, not a smarter model. For latency-sensitive pipelines, that trade-off will be worth it for some teams.