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Anthropic · Frontier

Claude Sonnet 5 Thinking

Added Jun 30, 2026

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Use in the app

Claude Sonnet 5 with adaptive thinking enabled for complex coding, planning, and agentic work.

  • Reasoning
  • Tools
  • Vision
  • Structured output
  • PDF input
Input
Text, Images
Output
Text
Reasoning effort
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
$4.00 for a 1-hour cache

Reference prices as published by the model provider. API example

Specifications

Context window
1M
Max output
128K
Average output (7 days)
2.6K tokens
Longer than 95% of 473 models

Side by side

Claude Sonnet 5 Thinking compared

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

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Claude Sonnet 5 ThinkingAnthropicThis modelGPT 5.5OpenAIRemove
ProviderAnthropicOpenAI
Discovery tierFrontierFrontier
AddedJun 30, 2026Apr 23, 2026
Limits
Context window1M1.05MBest
Max output128K128K
Average output2.6K tokens490 tokens
Pricing, USD per 1M tokens
Input$2.00Best$5.00
Output$10.00Best$30.00
Cache read$0.20Best$0.50
Cache write$2.50—
Performance
Throughput74.8 tok/s—
Time to first token3.2 s—
Request success (24h)100.0%100.0%
Benchmark indexes
Intelligence Index38.238.4Best
Coding Index71.574.9Best
Capabilities
ReasoningYesYes
ToolsYesYes
VisionYesYes
Structured outputYesYes
PDF inputYesYes
Reasoning effortlow, medium, high, xhigh, maxnone, low, medium, high, xhigh

Public evaluations

Benchmarks

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

  • Claude Sonnet 5 Thinking
  • GPT 5.5

Intelligence Index

  • Claude Sonnet 5 Thinking38.2
  • GPT 5.538.4

Claude Sonnet 5 Thinking tested at max reasoning effort

Claude Sonnet 5 Thinking: Better than 82% of 326 scored models

3.8Catalog models by score55.1

Indexes

  • Coding Index

    Composite of the coding evaluations

    • Claude Sonnet 5 Thinking: 71.5
    • GPT 5.5: 74.9Top

Agentic work

  • AutomationBench-AA

    Workflow automation, penalized for guardrail violations

    • Claude Sonnet 5 Thinking: 36.5%
    • GPT 5.5: 47.3%Top

  • AutomationBench-AA tasks completed

    Workflows finished end to end without a guardrail violation

    • Claude Sonnet 5 Thinking: 10.8%
    • GPT 5.5: 19.6%Top

  • AA-Briefcasev1.1

    Agentic knowledge work, rated head to head

    • Claude Sonnet 5 Thinking: 1,357 EloTop
    • GPT 5.5: 1,136 Elo

  • GDPval-AAv2.1

    Economically valuable occupational tasks, rated head to head

    • Claude Sonnet 5 Thinking: 1,464 EloTop
    • GPT 5.5: 1,351 Elo

Document reasoning

  • GDP.pdf

    Professional reasoning over PDF documents, all-pass rate

    • Claude Sonnet 5 Thinking: 13.2%
    • GPT 5.5: 21.2%Top

  • AA-LCRv1.1

    Reasoning across long documents

    • Claude Sonnet 5 Thinking: 82.0%
    • GPT 5.5: 84.3%Top

  • MLCR-AA

    Long-context reasoning over medical records

    • Claude Sonnet 5 Thinking: 5.0%
    • GPT 5.5: 28.9%Top

Reasoning and knowledge

  • Humanity’s Last Exam

    Expert-level questions across academic fields

    • Claude Sonnet 5 Thinking: 41.3%
    • GPT 5.5: 45.8%Top

  • GPQA Diamond

    Graduate-level science questions

    • Claude Sonnet 5 Thinking: 91.1%
    • GPT 5.5: 93.5%Top

  • IFBench

    Following precise output instructions

    • Claude Sonnet 5 Thinking: —
    • GPT 5.5: 75.9%

Coding

  • Terminal-Benchv4.0

    Practical software engineering in a terminal

    • Claude Sonnet 5 Thinking: 14.1%
    • GPT 5.5: 14.6%Top

  • SciCode

    Scientific computing in Python

    • Claude Sonnet 5 Thinking: 54.3%
    • GPT 5.5: 55.8%Top

Legacy evaluations

  • Terminal-Bench Hard

    Earlier terminal task suite

    • Claude Sonnet 5 Thinking: —
    • GPT 5.5: 60.6%

  • τ²-Bench Telecom

    Tool use in a customer-support simulation

    • Claude Sonnet 5 Thinking: —
    • GPT 5.5: 93.9%

  • AA-LCR (unversioned)

    Long-context reasoning, earlier grading

    • Claude Sonnet 5 Thinking: 82.0%
    • GPT 5.5: 84.3%Top

Scores from Artificial Analysis, updated Oct 26, 2026. Claude Sonnet 5 Thinking was tested at max reasoning effort; compare scores measured at the same effort.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.

Throughput
74.8 tok/s
Faster than 50% of 256 models
Time to first token
3.2 s
Quicker than 47% of 256 models
Prompt cache hits
70.5%
About $0.73 per 1M input tokens with caching
Request success (24h)
100.0%
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 94.1%
  • 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": "anthropic/claude-sonnet-5: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="anthropic/claude-sonnet-5:thinking",
    messages=[{"role": "user", "content": "Explain this stack trace."}],
)
print(reply.choices[0].message.content)

Anthropic

Other Anthropic models, starting with the same family.