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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 Pro 3upstageRemove
Providerupstageupstage
Discovery tierEfficientEfficient
AddedAug 11, 2026Mar 3, 2026
Limits
Context window524.29KBest131.07K
Max output131.07K—
Average output1.7K tokens—
Pricing, USD per 1M tokens
Input$0.03Best$0.15
Output$0.12Best$0.60
Cache read$0.006Best$0.015
Performance
Request success (24h)99.6%—
Benchmark indexes
Intelligence Index26.6Best7.8
Coding Index—16.2
Capabilities
ReasoningYesNo
ToolsYesNo
Structured outputYesNo
Reasoning effortnone, 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 Pro 3

Intelligence Index

  • Solar Pro 4 Thinking26.6
  • Solar Pro 37.8

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

3.8Catalog models by score55.1

Indexes

  • Coding Index

    Composite of the coding evaluations

    • Solar Pro 4 Thinking: —
    • Solar Pro 3: 16.2

Agentic work

  • AutomationBench-AA

    Workflow automation, penalized for guardrail violations

    • Solar Pro 4 Thinking: 13.6%Top
    • Solar Pro 3: 0.5%

  • AutomationBench-AA tasks completed

    Workflows finished end to end without a guardrail violation

    • Solar Pro 4 Thinking: 2.4%Top
    • Solar Pro 3: 0.0%

  • AA-Briefcasev1.1

    Agentic knowledge work, rated head to head

    • Solar Pro 4 Thinking: 1,093 EloTop
    • Solar Pro 3: 99 Elo

  • GDPval-AAv2.1

    Economically valuable occupational tasks, rated head to head

    • Solar Pro 4 Thinking: 1,106 EloTop
    • Solar Pro 3: 264 Elo

Document reasoning

  • GDP.pdf

    Professional reasoning over PDF documents, all-pass rate

    • Solar Pro 4 Thinking: 7.0%Top
    • Solar Pro 3: 1.6%

  • AA-LCRv1.1

    Reasoning across long documents

    • Solar Pro 4 Thinking: 70.7%Top
    • Solar Pro 3: 32.3%

  • MLCR-AA

    Long-context reasoning over medical records

    • Solar Pro 4 Thinking: —
    • Solar Pro 3: 0.6%

Reasoning and knowledge

  • Humanity’s Last Exam

    Expert-level questions across academic fields

    • Solar Pro 4 Thinking: 29.8%Top
    • Solar Pro 3: 10.3%

  • GPQA Diamond

    Graduate-level science questions

    • Solar Pro 4 Thinking: 89.1%Top
    • Solar Pro 3: 72.4%

  • IFBench

    Following precise output instructions

    • Solar Pro 4 Thinking: —
    • Solar Pro 3: 71.2%

Coding

  • Terminal-Benchv4.0

    Practical software engineering in a terminal

    • Solar Pro 4 Thinking: 0.0%Top
    • Solar Pro 3: 0.0%Top

  • SciCode

    Scientific computing in Python

    • Solar Pro 4 Thinking: 48.0%Top
    • Solar Pro 3: 25.5%

Legacy evaluations

  • Terminal-Bench Hard

    Earlier terminal task suite

    • Solar Pro 4 Thinking: —
    • Solar Pro 3: 7.6%

  • τ²-Bench Telecom

    Tool use in a customer-support simulation

    • Solar Pro 4 Thinking: —
    • Solar Pro 3: 86.3%

  • AA-LCR (unversioned)

    Long-context reasoning, earlier grading

    • Solar Pro 4 Thinking: 70.7%Top
    • Solar Pro 3: 32.3%

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

Other upstage models, starting with the same family.