GPT-5.6 Luna Pro vs GPT-6 Astra Pro
GPT-5.6 Luna Pro costs 41.7x less per output token than GPT-6 Astra Pro ($1.20 vs $50.00 per million). Updated October 22, 2026; no benchmark has tested both models yet.
- Coding
- No data
- Overall
- No data
- Output $/M
- $1.20
- Coding
- No data
- Overall
- No data
- Output $/M
- $50.00
GPT-5.6 Luna Pro or GPT-6 Astra Pro: which to pick
Neither model has a coding score yet, so the two cannot be ranked on coding.
Pick GPT-5.6 Luna Pro for output tokens 41.7x cheaper ($1.20 vs $50.00 per million).
No benchmark has tested both yet. GPT-5.6 Luna Pro has none yet; GPT-6 Astra Pro on WeirdML and Chess puzzles. Compare them on price and context instead.
Which one for your work
Each card is decided by one number both models carry. Where only one has it, the card says so and makes no call.
Coding
Vibe Coding Index, six public coding benchmarks
No call
Neither has a coding score yet.
One side not measured
Long documents
Listed context window
No call
Both take 1.05M tokens.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
GPT-5.6 Luna Pro
GPT-5.6 Luna Pro $0.0008, GPT-6 Astra Pro $0.035 per turn.
List prices
At a glance
- Coding index
- GPT-5.6 Luna Pro not benchmarked, GPT-6 Astra Pro not benchmarked.
- Widest category
- None yet: no category has been tested on both models.
- Widest single gap
- None yet: no benchmark has tested both models.
- Output price
- GPT-5.6 Luna Pro $1.20 against GPT-6 Astra Pro $50.00 per million output tokens, 41.7x apart.
- Context window
- Both take 1.05M tokens.
Benchmark by benchmark
Every board either model has a result on, a category to a fold; bars are each result on a 0 to 100 scale. Only one model is measured on each, so no row names a leader.
CodingDirectional onlySix of these boards feed the Vibe Coding Index1 board measured
| Benchmark | GPT-5.6 Luna Pro | GPT-6 Astra Pro | Leader |
|---|---|---|---|
| WeirdML | Not measured | 93.6% | Only GPT-6 Astra Pro measured |
| Neither model has a result on the other 42 boards here | |||
ReasoningDirectional onlyPublic boards, shown as published, kept out of the index1 board measured
| Benchmark | GPT-5.6 Luna Pro | GPT-6 Astra Pro | Leader |
|---|---|---|---|
| Chess puzzles | Not measured | 76.0% | Only GPT-6 Astra Pro measured |
| Neither model has a result on the other 22 boards here | |||
What each workload costs
Three fixed token mixes at each model's listed price, so per-token rates become a bill.
Chat turn
1K input + 500 output tokens
GPT-5.6 Luna Pro costs less
Repository review
50K input + 3K output tokens
GPT-5.6 Luna Pro costs less
Agent loop
200K input + 10K output tokens
GPT-5.6 Luna Pro costs less
Listed OpenRouter rates, without cache or batch discounts. A workload that does not fit a model's context window would need splitting.
Specification differences
The leading value in a row is marked; a row with a missing value names no leader. Our two rows are marked in red.
| Specification | OpenAI GPT-5.6 Luna Pro | OpenAI GPT-6 Astra Pro |
|---|---|---|
| Maker | OpenAI | OpenAI |
| Weights | No public weights listed | No public weights listed |
| Released | July 9, 2026 | September 4, 2026 |
| Context window | 1.05M | 1.05M |
| Input $/Mtok | $0.20 | $10.00 |
| Output $/Mtok | $1.20 | $50.00 |
| Coding index | Not benchmarked | Not benchmarked |
| Independent measurements behind it | 0 | 0 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is GPT-5.6 Luna Pro better than GPT-6 Astra Pro for coding?
Neither model has a coding score yet, so the two cannot be ranked on coding. Pick GPT-5.6 Luna Pro for output tokens 41.7x cheaper ($1.20 vs $50.00 per million).
Which is cheaper, GPT-5.6 Luna Pro or GPT-6 Astra Pro?
GPT-5.6 Luna Pro costs $0.20 per million input tokens and $1.20 per million output tokens; GPT-6 Astra Pro costs $10.00 and $50.00. Cost per solved task is known for neither of them.
Which has the bigger context window, GPT-5.6 Luna Pro or GPT-6 Astra Pro?
Neither: both take 1.05M tokens.
Has any benchmark tested both GPT-5.6 Luna Pro and GPT-6 Astra Pro?
No benchmark has tested both yet. GPT-5.6 Luna Pro has none yet; GPT-6 Astra Pro on WeirdML and Chess puzzles. Compare them on price and context instead. Data as of October 22, 2026.