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upstage · Efficient

Solar Pro 4 Thinking

Added Aug 11, 2026

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Use in the app

Upstage's Solar Pro 4 with reasoning enabled for harder agentic workflows, document-intensive work, coding, planning, and analysis across a 524K-token context window.

  • Reasoning
  • Tools
  • Structured output
Input
Text
Output
Text
Reasoning effort
none · low · medium · high
Discovery tier
Efficient

Pricing

USD per 1M tokens
Input
$0.03
Output
$0.12
Cache read
$0.006

Reference prices as published by the model provider. API example

Specifications

Context window
524.3K
Max output
131.1K
Average output (7 days)
1.7K tokens
Longer than 88% of 465 models

Side by side

Solar Pro 4 Thinking compared

Specifications, prices, speed and benchmark scores next to each other. Benchmarks below show every compared model too.

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Solar Pro 4 ThinkingupstageThis modelSolar Mini 4 ThinkingupstageRemove
Providerupstageupstage
Discovery tierEfficientEfficient
AddedAug 11, 2026Sep 23, 2026
Limits
Context window524.29K524.29K
Max output131.07K131.07K
Average output1.7K tokens2.8K tokens
Pricing, USD per 1M tokens
Input$0.03Best$0.05
Output$0.12Best$0.20
Cache read$0.006$0.005Best
Performance
Request success (24h)99.6%—
Benchmark indexes
Intelligence Index26.6—
Capabilities
ReasoningYesYes
ToolsYesYes
Structured outputYesYes
Reasoning effortnone, low, medium, highnone, low, medium, high

Public evaluations

Benchmarks

Independent evaluation results, with how each score ranks among the models in the Noumen catalog.

  • Solar Pro 4 Thinking
  • Solar Mini 4 Thinking

Intelligence Index

  • Solar Pro 4 Thinking26.6
  • Solar Mini 4 Thinking—

Solar Pro 4 Thinking: Better than 67% of 326 scored models

3.8Catalog models by score55.1

Agentic work

  • AutomationBench-AA

    Workflow automation, penalized for guardrail violations

    • Solar Pro 4 Thinking: 13.6%
    • Solar Mini 4 Thinking: —

  • AutomationBench-AA tasks completed

    Workflows finished end to end without a guardrail violation

    • Solar Pro 4 Thinking: 2.4%
    • Solar Mini 4 Thinking: —

  • AA-Briefcasev1.1

    Agentic knowledge work, rated head to head

    • Solar Pro 4 Thinking: 1,093 Elo
    • Solar Mini 4 Thinking: —

  • GDPval-AAv2.1

    Economically valuable occupational tasks, rated head to head

    • Solar Pro 4 Thinking: 1,106 Elo
    • Solar Mini 4 Thinking: —

Document reasoning

  • GDP.pdf

    Professional reasoning over PDF documents, all-pass rate

    • Solar Pro 4 Thinking: 7.0%
    • Solar Mini 4 Thinking: —

  • AA-LCRv1.1

    Reasoning across long documents

    • Solar Pro 4 Thinking: 70.7%
    • Solar Mini 4 Thinking: —

Reasoning and knowledge

  • Humanity’s Last Exam

    Expert-level questions across academic fields

    • Solar Pro 4 Thinking: 29.8%
    • Solar Mini 4 Thinking: —

  • GPQA Diamond

    Graduate-level science questions

    • Solar Pro 4 Thinking: 89.1%
    • Solar Mini 4 Thinking: —

Coding

  • Terminal-Benchv4.0

    Practical software engineering in a terminal

    • Solar Pro 4 Thinking: 0.0%
    • Solar Mini 4 Thinking: —

  • SciCode

    Scientific computing in Python

    • Solar Pro 4 Thinking: 48.0%
    • Solar Mini 4 Thinking: —

Legacy evaluations

  • AA-LCR (unversioned)

    Long-context reasoning, earlier grading

    • Solar Pro 4 Thinking: 70.7%
    • Solar Mini 4 Thinking: —

Scores from Artificial Analysis, updated Oct 26, 2026. Artificial Analysis

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.

Prompt cache hits
19.1%
About $0.0254 per 1M input tokens with caching
Request success (24h)
99.5%
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.

Hourly request success · last 72 hoursLowest hour 85.7%
  • 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.

Read the quickstart
curl https://www.noumen.xyz/api/v1/chat/completions \
  -H "Authorization: Bearer $NOUMEN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "upstage/solar-pro4:thinking",
    "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="upstage/solar-pro4:thinking",
    messages=[{"role": "user", "content": "Explain this stack trace."}],
)
print(reply.choices[0].message.content)

upstage

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