OpenAI · Released Sep 22, 2026GPT-6 Luna
OpenAI's most efficient model for focused, high-volume tasks.
- Capability
- —No ECI score yet
- Input
- $0.10per 1M tokens
- Output
- $0.50per 1M tokens
- Context
- 1.05M128K max output
What it costs
- Input
- $0.10per million tokens
- Output
- $0.50per million tokens
- Cached input
- $0.01per million tokens
- Cache write
- $0.125per million tokens
- Over 272K tokens
- $0.20 / $0.75input / output per million
- Blended (3:1)
- $0.20cheaper than 78% of priced models
Typical monthly bills
| Monthly usage | Estimated cost |
|---|---|
| Side project2M input + 0.5M output tokens | $0.45 |
| Team assistant25M input + 5M output tokens | $5.00 |
| Production app250M input + 50M output tokens | $50.00 |
Official OpenAI API price, as listed on models.dev.
Independent benchmarks
Epoch AI has not published a Capabilities Index score for GPT-6 Luna yet.
Scores from Epoch AI, run independently of OpenAI.
The details
- Lab
- OpenAI
- Released
- Sep 22, 2026
- Knowledge cutoff
- May 18, 2026
- Context window
- 1,050,000 tokens
- Max output
- 128,000 tokens
- Inputs
- Text, Images, PDFs
- Output
- Text
- Reasoning
- Adjustable effort low · medium · high · xhigh · max
- Tool calling
- Yes
- Structured output
- Yes
- Weights
- Proprietary
- API model ID
gpt-6-lunaon OpenAI- Availability
- 24 API providerslisted on models.dev
What OpenAI claims
Published by the lab at launch. Settings vary, so compare these only with care.
| Benchmark | Score | Setting | Source |
|---|---|---|---|
| DeepSWE v1.1 | 66.6 | max effort | Source |
More from OpenAI
About GPT-6 Luna
How much does GPT-6 Luna cost?
GPT-6 Luna costs $0.10 input / $0.50 output per million tokens (official OpenAI API price). Cached input is $0.01 per million tokens, and writing to the cache costs $0.125. Requests over 272K tokens are billed at $0.20 input / $0.75 output. At a 3:1 input-to-output mix that is $0.20 per million tokens, cheaper than 78% of the 360 priced models we track.
What is the context window of GPT-6 Luna?
GPT-6 Luna accepts up to 1,050,000 tokens per request and can write up to 128,000 tokens in one response.
How good is GPT-6 Luna?
Epoch AI has not published a Capabilities Index score for GPT-6 Luna yet. Epoch AI benchmark results: GPQA Diamond 90.5%, FrontierMath Tiers 1–3 79.0%, OTIS Mock AIME 2024–2025 98.9%, SimpleQA Verified 41.4%.
Is GPT-6 Luna open source?
No. GPT-6 Luna is proprietary; you use it through OpenAI’s API or partner platforms.
What inputs does GPT-6 Luna support?
GPT-6 Luna accepts text, images and PDFs and replies in text. It is a reasoning model with low, medium, high, xhigh and max effort settings, supports tool calling and can return structured JSON output.
When was GPT-6 Luna released?
OpenAI released GPT-6 Luna on Sep 22, 2026. Its training data runs to May 18, 2026.
What are the best alternatives to GPT-6 Luna?
The closest current models from other labs on capability, price and release date are GLM-5.3-Flash (Z.ai (Zhipu), ECI 151.9, $0.15 / $0.50), DeepSeek V4 Flash 0731 (DeepSeek, ECI 154.5, $0.14 / $0.28), MiniMax-M3 (MiniMax, ECI 147.0, $0.30 / $1.20) and Inkling Small (Thinking Machines, ECI 150.2, $0.50 / $1.20).