GPT-6 pricing: Astra, Sol, Terra and Luna
OpenAI's GPT-6 family is four models at four price points, from the flagship Astra to the high-volume Luna. This page lists each model's price, positioning and what a request costs. For every OpenAI model see the OpenAI API pricing guide; the wider section is AI costs and pricing.
Prices last verified against official provider pages on . How we verify prices. Written by the Chelure Enterprises Editorial Team.
Prices per million tokens
| Model | Input | Output | Cached input (read) | Cache write (5 min) | Batch API | Announced change |
|---|---|---|---|---|---|---|
| GPT-6 Astra | $10.00 | $50.00 | $1.00 | - | - | - |
| GPT-6.1 Sol | $2.00 | $10.00 | $0.10 | - | - | - |
| GPT-6.1 Terra | $1.00 | $5.00 | $0.05 | - | - | - |
| GPT-6 Luna | $0.10 | $0.50 | $0.01 | - | - | - |
Verified November 13, 2026 against the provider's pricing page. Compare every provider in the price comparison, or model your own workload in the cost calculator.
What each model is for
| Model | Positioning (provider) | Context window | Max output |
|---|---|---|---|
| GPT-6 Astra | Most capable model for the most demanding work | 1.05M | 128K tokens |
| GPT-6.1 Sol | Near-Astra performance for complex work at a lower cost | 1.05M | 128K tokens |
| GPT-6.1 Terra | Fast, efficient model for visual reasoning, computer use, and writing | 1.05M | 128K tokens |
| GPT-6 Luna | Most efficient model for focused, high-volume tasks | 1.05M | 128K tokens |
What a request costs
Costs per single request, from the prices above. Agent step uses cache reads at each model's cached-input rate.
| Model | Chat turn (1,500 input / 400 output tokens, no caching) | RAG answer (8,000 input / 500 output tokens, no caching) | Agent step (30,000 input / 2,000 output tokens, 80% of input read from cache) | 1,000 chat turns |
|---|---|---|---|---|
| GPT-6 Astra | $0.035 | $0.105 | $0.184 | $35.00 |
| GPT-6.1 Sol | $0.0070 | $0.021 | $0.034 | $7.00 |
| GPT-6.1 Terra | $0.0035 | $0.011 | $0.017 | $3.50 |
| GPT-6 Luna | $0.0003 | $0.0010 | $0.0018 | $0.35 |
Astra, Sol, Terra and Luna compared
Astra lists at $10 input and $50 output per million tokens, five times Sol's $2 and $10, so the question for most teams is whether Astra's extra capability is worth five times the bill. OpenAI says Sol delivers near-Astra performance at a lower cost, which makes Sol the natural starting point for complex work. Terra at $1 and $5 and Luna at $0.10 and $0.50 step down for speed and volume.
Caching changes the comparison. OpenAI's cached reads cost 0.1 times the input price, or 0.05 times for Sol and Terra, so on a prompt that is mostly cached Sol's effective input price falls to $0.10 per million, the same as Luna's uncached input price. The agent-step row in the table shows this effect. Our prompt caching guide explains the write fee that comes with it, and the GPT vs Claude cost page compares the families directly.
Frequently asked questions
How much does GPT-6 cost?
It depends on the model: GPT-6 Astra is $10 input and $50 output per million tokens, GPT-6.1 Sol is $2 and $10, GPT-6.1 Terra is $1 and $5, and GPT-6 Luna is $0.10 and $0.50, from OpenAI's pricing as recorded in our table.
Which GPT-6 model should I use?
OpenAI positions Astra for the most demanding work, Sol for near-Astra performance at a lower cost, Terra for fast, efficient visual reasoning, computer use and writing, and Luna for focused, high-volume tasks.
What is the GPT-6 context window?
OpenAI lists 1.05M tokens of context and 128K tokens of maximum output for all four models.
How much cheaper are cached tokens?
OpenAI's prompt caching guide says cached reads cost 0.1 times the normal input rate, or 0.05 times for GPT-6.1 Sol and GPT-6.1 Terra. Writes cost 1.25 times for the 30-minute cache on GPT-5.6 and later.
What are the knowledge cutoffs?
OpenAI lists April 30, 2026 for Astra and Sol, June 1, 2026 for Terra and May 18, 2026 for Luna.
Sources
Primary sources opened on November 13, 2026. Prices come from our verified price table (see the methodology).