OpenAI · Frontier
GPT 5.6 Sol
GPT-5.6 Sol is the flagship model in OpenAI's GPT-5.6 series. It is suited for complex reasoning, coding, agentic workflows, command-line work, and multi-step professional tasks.
- Reasoning
- Tools
- Vision
- Structured output
- PDF input
- Input
- Text, Images
- Output
- Text
- Reasoning effort
- none · low · medium · high · xhigh · max
- Discovery tier
- Frontier
Pricing
USD per 1M tokens- Input
- $2.00
- Output
- $10.00
- Cache read
- $0.20
- Cache write
- $2.50
Reference prices as published by the model provider. API example
Specifications
- Context window
- 1.1M
- Max output
- 128K
- Average output (7 days)
- 576 tokens
- Longer than 54% of 473 models
Side by side
Compare models
Put GPT 5.6 Sol next to up to three other models. The comparison stays in the link, so you can share it.
Public evaluations
Benchmarks
Independent evaluation results, with how each score ranks among the models in the Noumen catalog.
Intelligence Index
47.0
Tested at max reasoning effort
Better than 94% of 326 scored models
Indexes
Coding Index
77.4Composite of the coding evaluations
Better than 97% of 168 scored models
Agentic work
AutomationBench-AA
60.1%Workflow automation, penalized for guardrail violations
Better than 82% of 173 scored models
AutomationBench-AA tasks completed
30.3%Workflows finished end to end without a guardrail violation
Better than 86% of 173 scored models
AA-Briefcasev1.1
1,479 EloAgentic knowledge work, rated head to head
Better than 80% of 166 scored models
GDPval-AAv2.1
1,609 EloEconomically valuable occupational tasks, rated head to head
Better than 85% of 187 scored models
Document reasoning
GDP.pdf
27.2%Professional reasoning over PDF documents, all-pass rate
Better than 92% of 171 scored models
AA-LCRv1.1
84.0%Reasoning across long documents
Better than 94% of 309 scored models
MLCR-AA
30.0%Long-context reasoning over medical records
Better than 92% of 121 scored models
Reasoning and knowledge
Humanity’s Last Exam
49.5%Expert-level questions across academic fields
Better than 94% of 323 scored models
GPQA Diamond
94.1%Graduate-level science questions
Better than 96% of 291 scored models
IFBench
72.7%Following precise output instructions
Better than 80% of 215 scored models
Coding
Terminal-Benchv4.0
39.9%Practical software engineering in a terminal
Better than 85% of 171 scored models
SciCode
57.1%Scientific computing in Python
Better than 80% of 174 scored models
Legacy evaluations
Terminal-Bench Hard
65.9%Earlier terminal task suite
Better than 99% of 212 scored models
τ²-Bench Telecom
85.1%Tool use in a customer-support simulation
Better than 67% of 214 scored models
AA-LCR (unversioned)
84.0%Long-context reasoning, earlier grading
Better than 94% of 309 scored models
Scores from Artificial Analysis, updated Oct 26, 2026. GPT 5.6 Sol was tested at max reasoning effort; compare scores measured at the same effort.Artificial Analysis
- #10Roleplay34.3%
- #13Creative writing28.5%
- #4Coding31.4%
- #19Math0.0%
Ranks among Noumen catalog models on Use cases leaderboards. Only top-20 placements are listed.
- #16Overall1485.1
- #15Coding1533.6
- #19Math1496.0
- #15Longer Query1498.5
- #13Creative Writing1469.8
- #10Instruction Following1490.7
- #14Hard Prompts1511.5
- #11Chinese1540.6
- #16Exclude Ties1500.8
- #9Expert1532.1
- #16French1506.0
- #7German1504.5
- #18Hard Prompts English1509.1
- #13Industry Business And Management And Financial Operations1487.0
- #10Industry Entertainment And Sports And Media1470.8
- #14Industry Legal And Government1497.1
- #12Industry Mathematical1512.0
- #16Industry Software And It Services1522.8
- #11Industry Writing And Literature And Language1481.5
- #10Japanese1496.8
- #14Korean1455.2
- #15Multi Turn1489.7
- #16Non English1475.7
- #11Polish1495.5
- #12Russian1497.4
- #12Vision Style Control Overall1286.2
- #11Vision Style Control · Creative Writing Vision1289.0
- #15Vision Style Control · Diagram1318.5
- #8Vision Style Control · English1283.7
- #17Vision Style Control · Homework1313.9
- #1Search Overall1261.1
- #7Document Overall1482.7
- #6Document Style Control Overall1488.7
Ranks among Noumen catalog models on LMArena leaderboards. Only top-20 placements are listed.LMArena
- #12FrontierCode Main47.5%
- #10FrontierCode Extended60.6%
Ranks among Noumen catalog models on FrontierCode leaderboards. Only top-20 placements are listed.FrontierCode
- #11Epoch Capabilities Index162.8
Ranks among Noumen catalog models on Epoch AI leaderboards. Only top-20 placements are listed.Epoch AI
- #10ARC-AGI-197.5%
- #4ARC-AGI-292.5%
- #7ARC-AGI-3 (Default harness)7.8%
Ranks among Noumen catalog models on ARC Prize leaderboards. Only top-20 placements are listed.ARC Prize
- #12EQ-Bench 41240
- #11Creative Writing v31974
- #12Longform Writing81.7
Ranks among Noumen catalog models on EQ-Bench leaderboards. Only top-20 placements are listed.EQ-Bench
- #9Game Development1367
- #8Website1321
- #12UI Component1332
- #10Data Visualization1323
- #5SVG1311
- #113D1381
- #5ASCII Art1305
- #2Agentic Game Dev1232
- #10Web Apps1245
- #7Full Stack1262
- #5Native Apps1239
- #7Mobile Apps1242
Ranks among Noumen catalog models on Design Arena leaderboards. Only top-20 placements are listed.Design Arena
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
- 141.1 tok/s
- Faster than 75% of 260 models
- Time to first token
- 4.9 s
- Quicker than 32% of 260 models
- Prompt cache hits
- 16.1%
- About $1.71 per 1M input tokens with caching
- Request success (24h)
- 99.4%
- 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-sol",
"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-sol",
messages=[{"role": "user", "content": "Explain this stack trace."}],
)
print(reply.choices[0].message.content)OpenAI
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