Rate
GPT-5.6 Luna vs GPT-6 Astra: price
GPT-5.6 Luna is 44.4× cheaper than GPT-6 Astra for a typical chat workload (1,500 tokens in, 500 out).
| Item | GPT-5.6 Luna | GPT-6 Astra |
|---|---|---|
| Input per 1M tokens | $0.20 | $10.00 |
| Output per 1M tokens | $1.20 | $50.00 |
| Cached input per 1M | $0.02 | $1.00 |
| 1,000 chat messages1,500 tokens in, 500 out each | $0.90 | $40.00 |
| Summarize a 50-page PDF30,000 tokens in, 1,000 out | $0.0072 | $0.35 |
| One coding-agent task60,000 tokens in, 4,000 out, no caching | $0.017 | $0.80 |
GPT-6 Astra: Prompts over 272K tokens: 2x input, 1.5x output.
List prices checked September 28, 2026. Price is half the story: see how people rate each one today.
GPT-5.6 Luna vs GPT-6 Astra in numbers
Output, usually the bigger part of the bill, costs $1.20 on GPT-5.6 Luna and $50.00 on GPT-6 Astra, so GPT-5.6 Luna is 41.7× cheaper there. Input costs $0.20 versus $10.00 per million tokens. For a coding-agent task (60,000 tokens in, 4,000 out) that is $0.017 on GPT-5.6 Luna and $0.80 on GPT-6 Astra. Both accept up to 1.05M tokens of context. GPT-5.6 Luna came out on July 9, 2026 and GPT-6 Astra on September 3, 2026.
Both are OpenAI models. Estimate your own bill for both in the cost calculator.
Which one feels dumber today?
- GPT-5.6 LunaOpenAI
–no votes yet - GPT-6 AstraOpenAI–no votes yet
Frequently asked questions
Is GPT-5.6 Luna or GPT-6 Astra cheaper?
GPT-5.6 Luna is 44.4× cheaper than GPT-6 Astra for a typical chat workload (1,500 tokens in, 500 out). Output, usually the bigger part of the bill, costs $1.20 on GPT-5.6 Luna and $50.00 on GPT-6 Astra, so GPT-5.6 Luna is 41.7× cheaper there.
Which is better, GPT-5.6 Luna or GPT-6 Astra?
It depends on the task, and price is only part of it. Check how people rate each one today on the GPT-5.6 Luna and GPT-6 Astra pages, and read what users report in Discussions.