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Claude Opus 4vsClaude Sonnet 4

Anthropic vs Anthropic — Side-by-side model comparison

Claude Sonnet 4 leads 2/5 categories

Head-to-Head Comparison

MetricClaude Opus 4Claude Sonnet 4
Provider
Arena Rank
#1
#3
Context Window
200K
200K
Input Pricing
$5.00/1M tokens
$3.00/1M tokens
Output Pricing
$25.00/1M tokens
$15.00/1M tokens
Parameters
Undisclosed
Undisclosed
Open Source
No
No
Best For
Complex reasoning, coding, agentic tasks
Coding, writing, long documents
Release Date
May 22, 2025
May 22, 2025

Claude Opus 4

Claude Opus 4 is Anthropic's most powerful AI model, holding the #1 position on the Chatbot Arena leaderboard. It represents a breakthrough in extended thinking and agentic capabilities, able to work autonomously on complex multi-step tasks for hours. With a 200K token context window, it excels at analyzing entire codebases, lengthy legal documents, and research papers in a single pass. The model demonstrates exceptional performance in coding (setting new benchmarks on SWE-bench), advanced reasoning, and nuanced writing tasks. Its agentic capabilities allow it to use tools, navigate computers, and execute multi-step workflows with minimal human oversight. Opus 4 is the preferred choice for enterprises requiring the highest quality output on mission-critical tasks where accuracy and depth matter more than speed or cost.

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Claude Sonnet 4

Claude Sonnet 4 is Anthropic's balanced mid-tier model, offering an excellent combination of intelligence, speed, and cost-effectiveness. It ranks among the top 5 models globally on arena benchmarks while being significantly more affordable than Opus 4. With a 200K token context window, Sonnet 4 handles long documents and complex codebases with ease. The model excels at coding tasks (strong SWE-bench performance), long-form writing, document analysis, and structured data extraction. Its extended thinking capabilities allow it to tackle complex problems while maintaining fast response times for everyday tasks. Sonnet 4 is the most popular Claude model for production applications, offering the best price-to-performance ratio in Anthropic's lineup. It supports tool use, vision capabilities, and works seamlessly in agentic workflows.

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Key Differences: Claude Opus 4 vs Claude Sonnet 4

1

Claude Opus 4 ranks higher in arena benchmarks (#1) indicating stronger overall performance.

2

Claude Sonnet 4 is 1.7x cheaper on average, making it the better choice for high-volume applications.

C

When to use Claude Opus 4

  • +You need the highest quality output based on arena rankings
  • +Quality matters more than cost
  • +Your use case involves complex reasoning, coding, agentic tasks
View full Claude Opus 4 specs →
C

When to use Claude Sonnet 4

  • +Budget is a concern and you need cost efficiency
  • +Your use case involves coding, writing, long documents
View full Claude Sonnet 4 specs →

Cost Analysis

At current pricing, Claude Sonnet 4 is 1.7x more affordable than Claude Opus 4. For a typical enterprise workload processing 100M tokens per month:

Claude Opus 4 monthly cost

$1,500

100M tokens/mo (50/50 in/out)

Claude Sonnet 4 monthly cost

$900

100M tokens/mo (50/50 in/out)

The Verdict

Claude Sonnet 4 wins our head-to-head comparison with 2 out of 5 category wins. It's the stronger choice for coding, writing, long documents, though Claude Opus 4 holds an edge in complex reasoning, coding, agentic tasks.

Last compared: March 2026 · Data sourced from public benchmarks and official pricing pages

Frequently Asked Questions

Which is better, Claude Opus 4 or Claude Sonnet 4?
In our head-to-head comparison, Claude Sonnet 4 leads in 2 out of 5 categories (arena rank, context window, input pricing, output pricing, and parameters). Claude Sonnet 4 excels at coding, writing, long documents, while Claude Opus 4 is better suited for complex reasoning, coding, agentic tasks. The best choice depends on your specific requirements, budget, and use case.
How does Claude Opus 4 pricing compare to Claude Sonnet 4?
Claude Opus 4 charges $5.00 per 1M input tokens and $25.00 per 1M output tokens. Claude Sonnet 4 charges $3.00 per 1M input tokens and $15.00 per 1M output tokens. Claude Sonnet 4 is the more affordable option, approximately 1.7x cheaper on average. For high-volume production workloads, the pricing difference can significantly impact total cost of ownership.
What is the context window difference between Claude Opus 4 and Claude Sonnet 4?
Claude Opus 4 supports a 200K token context window, while Claude Sonnet 4 supports 200K tokens. Context window size matters most for tasks involving long documents, large codebases, or extended conversations.
Can I use Claude Opus 4 or Claude Sonnet 4 for free?
Claude Opus 4 is a paid API model starting at $5.00 per 1M input tokens. Claude Sonnet 4 is a paid API model starting at $3.00 per 1M input tokens.
Which model has better benchmarks, Claude Opus 4 or Claude Sonnet 4?
Claude Opus 4 holds arena rank #1, while Claude Sonnet 4 holds rank #3. Claude Opus 4 performs better in overall arena benchmarks, which aggregate human preference ratings across coding, reasoning, and general tasks. Note that benchmarks don't capture every use case — we recommend testing both models on your specific tasks.
Is Claude Opus 4 or Claude Sonnet 4 better for coding?
Claude Opus 4 is specifically optimized for coding tasks. Claude Sonnet 4 is specifically optimized for coding tasks. For coding specifically, arena rank and code-specific benchmarks are the best indicators of performance.