Anthropic · Frontier
Claude Sonnet 5 Thinking
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.
| Claude Sonnet 5 ThinkingAnthropicThis model | Grok 4.5xAIRemove | |
|---|---|---|
| Provider | Anthropic | xAI |
| Discovery tier | Frontier | Frontier |
| Added | Jun 30, 2026 | Jul 8, 2026 |
| Limits | ||
| Context window | 1MBest | 500K |
| Max output | 128K | — |
| Average output | 2.6K tokens | 1K tokens |
| Pricing, USD per 1M tokens | ||
| Input | $2.00 | $2.00 |
| Output | $10.00 | $6.00Best |
| Cache read | $0.20Best | $0.30 |
| Cache write | $2.50 | — |
| Performance | ||
| Throughput | 74.8 tok/sBest | 70.5 tok/s |
| Time to first token | 3.2 s | 1.7 sBest |
| Request success (24h) | 100.0% | 100.0% |
| Benchmark indexes | ||
| Intelligence Index | 38.2 | 38.8Best |
| Coding Index | 71.5 | 72.4Best |
| Capabilities | ||
| Reasoning | Yes | Yes |
| Tools | Yes | Yes |
| Vision | Yes | Yes |
| Structured output | Yes | Yes |
| PDF input | Yes | No |
| Reasoning effort | low, medium, high, xhigh, max | low, medium, high |
Public evaluations
Benchmarks
Independent evaluation results, with how each score ranks among the models in the Noumen catalog.
- Claude Sonnet 5 Thinking
- Grok 4.5
Intelligence Index
- Claude Sonnet 5 Thinking38.2
- Grok 4.538.8
Claude Sonnet 5 Thinking tested at max reasoning effort
Claude Sonnet 5 Thinking: Better than 82% of 326 scored models
Indexes
Coding Index
Composite of the coding evaluations
- Claude Sonnet 5 Thinking: 71.5
- Grok 4.5: 72.4Top
Agentic work
AutomationBench-AA
Workflow automation, penalized for guardrail violations
- Claude Sonnet 5 Thinking: 36.5%
- Grok 4.5: 57.9%Top
AutomationBench-AA tasks completed
Workflows finished end to end without a guardrail violation
- Claude Sonnet 5 Thinking: 10.8%
- Grok 4.5: 26.3%Top
AA-Briefcasev1.1
Agentic knowledge work, rated head to head
- Claude Sonnet 5 Thinking: 1,357 EloTop
- Grok 4.5: 1,278 Elo
GDPval-AAv2.1
Economically valuable occupational tasks, rated head to head
- Claude Sonnet 5 Thinking: 1,464 EloTop
- Grok 4.5: 1,381 Elo
Document reasoning
GDP.pdf
Professional reasoning over PDF documents, all-pass rate
- Claude Sonnet 5 Thinking: 13.2%
- Grok 4.5: 18.8%Top
AA-LCRv1.1
Reasoning across long documents
- Claude Sonnet 5 Thinking: 82.0%Top
- Grok 4.5: 79.3%
MLCR-AA
Long-context reasoning over medical records
- Claude Sonnet 5 Thinking: 5.0%
- Grok 4.5: 16.1%Top
Reasoning and knowledge
Humanity’s Last Exam
Expert-level questions across academic fields
- Claude Sonnet 5 Thinking: 41.3%
- Grok 4.5: 42.7%Top
GPQA Diamond
Graduate-level science questions
- Claude Sonnet 5 Thinking: 91.1%
- Grok 4.5: 93.1%Top
Coding
Terminal-Benchv4.0
Practical software engineering in a terminal
- Claude Sonnet 5 Thinking: 14.1%Top
- Grok 4.5: 10.6%
SciCode
Scientific computing in Python
- Claude Sonnet 5 Thinking: 54.3%
- Grok 4.5: 55.0%Top
Legacy evaluations
AA-LCR (unversioned)
Long-context reasoning, earlier grading
- Claude Sonnet 5 Thinking: 82.0%Top
- Grok 4.5: 79.3%
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
- Claude Sonnet 5 Thinking
- Grok 4.5
| Leaderboard | Claude Sonnet 5 Thinking | Grok 4.5 |
|---|---|---|
| Vision Style Control · Chinese | Not in top 20 | #16 · 1330.1 |
| Vision Style Control · Creative Writing Vision | Not in top 20 | #14 · 1280.9 |
| Search Overall | Not in top 20 | #10 · 1215.9 |
| Document Style Control Overall | Not in top 20 | #16 · 1464.3 |
Ranks among Noumen catalog models on LMArena leaderboards. Only top-20 placements are listed.LMArena
- Claude Sonnet 5 Thinking
- Grok 4.5
| Leaderboard | Claude Sonnet 5 Thinking | Grok 4.5 |
|---|---|---|
| FrontierCode Main | Not in top 20 | #20 · 42.4% |
| FrontierCode Extended | Not in top 20 | #18 · 56.5% |
Ranks among Noumen catalog models on FrontierCode leaderboards. Only top-20 placements are listed.FrontierCode
- Claude Sonnet 5 Thinking
- Grok 4.5
| Leaderboard | Claude Sonnet 5 Thinking | Grok 4.5 |
|---|---|---|
| ARC-AGI-3 (Default harness) | Not in top 20 | #16 · 0.3% |
Ranks among Noumen catalog models on ARC Prize leaderboards. Only top-20 placements are listed.ARC Prize
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.
- 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": "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
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