OpenAI · Efficient
GPT 5.6 Luna Pro
GPT-5.6 Luna with Pro reasoning mode. Pro mode performs more model work for difficult tasks; reasoning effort remains independently configurable and defaults to medium.
- Reasoning
- Tools
- Vision
- Structured output
- PDF input
- Input
- Text, Images
- Output
- Text
- Reasoning effort
- none · low · medium · high · xhigh · max
- Discovery tier
- Efficient
Pricing
USD per 1M tokens- Input
- $0.20
- Output
- $1.20
- Cache read
- $0.02
- Cache write
- $0.25
Reference prices as published by the model provider. API example
Specifications
- Context window
- 1.1M
- Max output
- 128K
- Average output (7 days)
- 1.5K tokens
- Longer than 87% of 465 models
Side by side
GPT 5.6 Luna Pro compared
Specifications, prices, speed and benchmark scores next to each other. Benchmarks below show every compared model too.
| GPT 5.6 Luna ProOpenAIThis model | GPT 6.1 SolOpenAIRemove | |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Discovery tier | Efficient | Frontier |
| Added | Jul 9, 2026 | Sep 29, 2026 |
| Limits | ||
| Context window | 1.05M | 1.05M |
| Max output | 128K | 128K |
| Average output | 1.5K tokens | 388 tokens |
| Pricing, USD per 1M tokens | ||
| Input | $0.20Best | $2.00 |
| Output | $1.20Best | $10.00 |
| Cache read | $0.02Best | $0.10 |
| Cache write | $0.25Best | $2.50 |
| Performance | ||
| Throughput | 949.8 tok/sBest | 145.8 tok/s |
| Time to first token | 9.6 s | 4.1 sBest |
| Request success (24h) | 99.8% | 99.9%Best |
| Benchmark indexes | ||
| Intelligence Index | 37.3 | 47.8Best |
| Coding Index | 71.4 | — |
| Capabilities | ||
| Reasoning | Yes | Yes |
| Tools | Yes | Yes |
| Vision | Yes | Yes |
| Structured output | Yes | Yes |
| PDF input | Yes | Yes |
| Reasoning effort | none, low, medium, high, xhigh, max | low, medium, high, xhigh, max |
Public evaluations
Benchmarks
Independent evaluation results, with how each score ranks among the models in the Noumen catalog.
- GPT 5.6 Luna Pro
- GPT 6.1 Sol
Intelligence Index
- GPT 5.6 Luna Pro37.3
- GPT 6.1 Sol47.8
GPT 5.6 Luna Pro tested at max reasoning effort
GPT 5.6 Luna Pro: Better than 81% of 326 scored models
Indexes
Coding Index
Composite of the coding evaluations
- GPT 5.6 Luna Pro: 71.4
- GPT 6.1 Sol: —
Agentic work
AutomationBench-AA
Workflow automation, penalized for guardrail violations
- GPT 5.6 Luna Pro: 50.2%
- GPT 6.1 Sol: 62.6%Top
AutomationBench-AA tasks completed
Workflows finished end to end without a guardrail violation
- GPT 5.6 Luna Pro: 18.6%
- GPT 6.1 Sol: 30.1%Top
AA-Briefcasev1.1
Agentic knowledge work, rated head to head
- GPT 5.6 Luna Pro: 1,339 Elo
- GPT 6.1 Sol: 1,359 EloTop
GDPval-AAv2.1
Economically valuable occupational tasks, rated head to head
- GPT 5.6 Luna Pro: 1,460 EloTop
- GPT 6.1 Sol: 1,450 Elo
Document reasoning
GDP.pdf
Professional reasoning over PDF documents, all-pass rate
- GPT 5.6 Luna Pro: 24.0%
- GPT 6.1 Sol: 30.0%Top
AA-LCRv1.1
Reasoning across long documents
- GPT 5.6 Luna Pro: 83.7%Top
- GPT 6.1 Sol: 83.3%
MLCR-AA
Long-context reasoning over medical records
- GPT 5.6 Luna Pro: 20.0%
- GPT 6.1 Sol: 32.2%Top
Reasoning and knowledge
Humanity’s Last Exam
Expert-level questions across academic fields
- GPT 5.6 Luna Pro: 39.5%
- GPT 6.1 Sol: 49.9%Top
GPQA Diamond
Graduate-level science questions
- GPT 5.6 Luna Pro: 91.1%
- GPT 6.1 Sol: —
Coding
Terminal-Benchv4.0
Practical software engineering in a terminal
- GPT 5.6 Luna Pro: 11.6%
- GPT 6.1 Sol: 48.0%Top
SciCode
Scientific computing in Python
- GPT 5.6 Luna Pro: 53.6%Top
- GPT 6.1 Sol: 53.2%
Legacy evaluations
AA-LCR (unversioned)
Long-context reasoning, earlier grading
- GPT 5.6 Luna Pro: 83.7%Top
- GPT 6.1 Sol: 83.3%
Scores from Artificial Analysis, updated Oct 26, 2026. GPT 5.6 Luna Pro was tested at max reasoning effort; compare scores measured at the same effort.Artificial Analysis
- GPT 5.6 Luna Pro
- GPT 6.1 Sol
| Leaderboard | GPT 5.6 Luna Pro | GPT 6.1 Sol |
|---|---|---|
| Combined | Not in top 20 | #14 · 13.8% |
Ranks among Noumen catalog models on Combined leaderboards. Only top-20 placements are listed.
- GPT 5.6 Luna Pro
- GPT 6.1 Sol
| Leaderboard | GPT 5.6 Luna Pro | GPT 6.1 Sol |
|---|---|---|
| Math | Not in top 20 | #7 · 24.4% |
Ranks among Noumen catalog models on Use cases leaderboards. Only top-20 placements are listed.
- GPT 5.6 Luna Pro
- GPT 6.1 Sol
| Leaderboard | GPT 5.6 Luna Pro | GPT 6.1 Sol |
|---|---|---|
| Coding | Not in top 20 | #12 · 1537.2 |
| Math | Not in top 20 | #7 · 1513.4 |
| Instruction Following | Not in top 20 | #15 · 1485.0 |
| English | Not in top 20 | #15 · 1491.0 |
| Expert | Not in top 20 | #18 · 1516.5 |
| French | Not in top 20 | #12 · 1507.5 |
| Hard Prompts English | Not in top 20 | #16 · 1509.5 |
| Industry Business And Management And Financial Operations | Not in top 20 | #14 · 1485.4 |
| Industry Entertainment And Sports And Media | Not in top 20 | #18 · 1459.4 |
| Industry Legal And Government | Not in top 20 | #15 · 1496.5 |
| Industry Mathematical | Not in top 20 | #2 · 1537.7 |
| Industry Software And It Services | Not in top 20 | #9 · 1528.5 |
| Spanish | Not in top 20 | #19 · 1477.3 |
| Vision Style Control Overall | Not in top 20 | #5 · 1293.5 |
| Vision Style Control · Creative Writing Vision | Not in top 20 | #2 · 1311.5 |
| Vision Style Control · Diagram | Not in top 20 | #13 · 1319.0 |
| Vision Style Control · English | Not in top 20 | #14 · 1279.4 |
| Vision Style Control · Homework | Not in top 20 | #1 · 1358.3 |
| WebDev Overall | Not in top 20 | #4 · 1749.3 |
| WebDev · Image To Webdev | Not in top 20 | #5 · 1701.7 |
| WebDev · Webdev | Not in top 20 | #4 · 1749.3 |
| WebDev · Webdev-html | Not in top 20 | #1 · 1793.8 |
| WebDev · Webdev-react | Not in top 20 | #5 · 1753.6 |
| Search Overall | Not in top 20 | #6 · 1233.1 |
Ranks among Noumen catalog models on LMArena leaderboards. Only top-20 placements are listed.LMArena
- GPT 5.6 Luna Pro
- GPT 6.1 Sol
| Leaderboard | GPT 5.6 Luna Pro | GPT 6.1 Sol |
|---|---|---|
| FrontierCode Main | Not in top 20 | #7 · 50.2% |
| FrontierCode Extended | Not in top 20 | #11 · 60.4% |
Ranks among Noumen catalog models on FrontierCode leaderboards. Only top-20 placements are listed.FrontierCode
- GPT 5.6 Luna Pro
- GPT 6.1 Sol
| Leaderboard | GPT 5.6 Luna Pro | GPT 6.1 Sol |
|---|---|---|
| Epoch Capabilities Index | Not in top 20 | #3 · 168.4 |
Ranks among Noumen catalog models on Epoch AI leaderboards. Only top-20 placements are listed.Epoch AI
- GPT 5.6 Luna Pro
- GPT 6.1 Sol
| Leaderboard | GPT 5.6 Luna Pro | GPT 6.1 Sol |
|---|---|---|
| ARC-AGI-1 | Not in top 20 | #6 · 98.5% |
| ARC-AGI-2 | Not in top 20 | #2 · 94.2% |
| ARC-AGI-3 (Default harness) | Not in top 20 | #2 · 52.7% |
Ranks among Noumen catalog models on ARC Prize leaderboards. Only top-20 placements are listed.ARC Prize
- GPT 5.6 Luna Pro
- GPT 6.1 Sol
| Leaderboard | GPT 5.6 Luna Pro | GPT 6.1 Sol |
|---|---|---|
| Game Development | Not in top 20 | #4 · 1407 |
| Website | Not in top 20 | #10 · 1315 |
| UI Component | Not in top 20 | #8 · 1339 |
| Data Visualization | Not in top 20 | #17 · 1291 |
| 3D | Not in top 20 | #5 · 1436 |
| Web Apps | Not in top 20 | #4 · 1306 |
| Mobile Apps | Not in top 20 | #8 · 1237 |
Ranks among Noumen catalog models on Design Arena leaderboards. Only top-20 placements are listed.Design Arena
- GPT 5.6 Luna Pro
- GPT 6.1 Sol
| Leaderboard | GPT 5.6 Luna Pro | GPT 6.1 Sol |
|---|---|---|
| Usage Share | Not in top 20 | #8 · 2.4% |
Ranks among Noumen catalog models on Usage leaderboards. Only top-20 placements are listed.
Live routing data
Performance and reliability
Recent averages across requests routed for this model. Your own speed depends on prompt length, reasoning effort and load.
- Throughput
- 949.8 tok/s
- Faster than 99% of 247 models
- Time to first token
- 9.6 s
- Quicker than 10% of 247 models
- Prompt cache hits
- 80.7%
- About $0.0548 per 1M input tokens with caching
- Request success (24h)
- 99.8%
- Reliable
Cache hits are the share of input tokens recently served from a prompt cache across all requests. They are not a forecast of your own hit rate.
- Healthy (98% or more)
- Degraded (90–98%)
- Down (under 90%)
- No requests
Developers
Use it through the API
Noumen’s API is OpenAI-compatible: any Chat Completions client works with a base URL and a key.
curl https://www.noumen.xyz/api/v1/chat/completions \
-H "Authorization: Bearer $NOUMEN_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "openai/gpt-5.6-luna-pro",
"reasoning_effort": "medium",
"messages": [{ "role": "user", "content": "Explain this stack trace." }]
}'import os
from openai import OpenAI
client = OpenAI(base_url="https://www.noumen.xyz/api/v1", api_key=os.environ["NOUMEN_API_KEY"])
reply = client.chat.completions.create(
model="openai/gpt-5.6-luna-pro",
messages=[{"role": "user", "content": "Explain this stack trace."}],
)
print(reply.choices[0].message.content)OpenAI
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