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Claude Sonnet 4vsClaude Haiku 4.5

Anthropic vs Anthropic — Side-by-side model comparison

Claude Haiku 4.5 leads 2/5 categories

Head-to-Head Comparison

MetricClaude Sonnet 4Claude Haiku 4.5
Provider
Arena Rank
#3
#15
Context Window
200K
200K
Input Pricing
$3.00/1M tokens
$1.00/1M tokens
Output Pricing
$15.00/1M tokens
$5.00/1M tokens
Parameters
Undisclosed
Undisclosed
Open Source
No
No
Best For
Coding, writing, long documents
Fast responses, classification, extraction
Release Date
May 22, 2025
Oct 1, 2025

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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Claude Haiku 4.5

Claude Haiku 4.5 is Anthropic's fastest and most affordable model in the Claude family, designed for high-throughput applications where speed and cost-efficiency are paramount. Despite being the lightest model in the lineup, it delivers surprisingly strong performance on classification, extraction, summarization, and simple reasoning tasks. With a 200K context window and pricing at just $1.00 per million input tokens, it's ideal for processing large volumes of data quickly — from customer support triage to content moderation to data extraction. Haiku 4.5 responds in milliseconds, making it suitable for real-time applications where users expect instant responses. It's the go-to choice for builders who need Claude's safety and quality characteristics at scale.

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Key Differences: Claude Sonnet 4 vs Claude Haiku 4.5

1

Claude Sonnet 4 ranks higher in arena benchmarks (#3) indicating stronger overall performance.

2

Claude Haiku 4.5 is 3.0x cheaper on average, making it the better choice for high-volume applications.

C

When to use Claude Sonnet 4

  • +You need the highest quality output based on arena rankings
  • +Quality matters more than cost
  • +Your use case involves coding, writing, long documents
View full Claude Sonnet 4 specs →
C

When to use Claude Haiku 4.5

  • +Budget is a concern and you need cost efficiency
  • +Your use case involves fast responses, classification, extraction
View full Claude Haiku 4.5 specs →

Cost Analysis

At current pricing, Claude Haiku 4.5 is 3.0x more affordable than Claude Sonnet 4. For a typical enterprise workload processing 100M tokens per month:

Claude Sonnet 4 monthly cost

$900

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

Claude Haiku 4.5 monthly cost

$300

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

The Verdict

Claude Haiku 4.5 wins our head-to-head comparison with 2 out of 5 category wins. It's the stronger choice for fast responses, classification, extraction, though Claude Sonnet 4 holds an edge in coding, writing, long documents.

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

Frequently Asked Questions

Which is better, Claude Sonnet 4 or Claude Haiku 4.5?
In our head-to-head comparison, Claude Haiku 4.5 leads in 2 out of 5 categories (arena rank, context window, input pricing, output pricing, and parameters). Claude Haiku 4.5 excels at fast responses, classification, extraction, while Claude Sonnet 4 is better suited for coding, writing, long documents. The best choice depends on your specific requirements, budget, and use case.
How does Claude Sonnet 4 pricing compare to Claude Haiku 4.5?
Claude Sonnet 4 charges $3.00 per 1M input tokens and $15.00 per 1M output tokens. Claude Haiku 4.5 charges $1.00 per 1M input tokens and $5.00 per 1M output tokens. Claude Haiku 4.5 is the more affordable option, approximately 3.0x 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 Sonnet 4 and Claude Haiku 4.5?
Claude Sonnet 4 supports a 200K token context window, while Claude Haiku 4.5 supports 200K tokens. Context window size matters most for tasks involving long documents, large codebases, or extended conversations.
Can I use Claude Sonnet 4 or Claude Haiku 4.5 for free?
Claude Sonnet 4 is a paid API model starting at $3.00 per 1M input tokens. Claude Haiku 4.5 is a paid API model starting at $1.00 per 1M input tokens.
Which model has better benchmarks, Claude Sonnet 4 or Claude Haiku 4.5?
Claude Sonnet 4 holds arena rank #3, while Claude Haiku 4.5 holds rank #15. Claude Sonnet 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 Sonnet 4 or Claude Haiku 4.5 better for coding?
Claude Sonnet 4 is specifically optimized for coding tasks. Claude Haiku 4.5's primary strength is fast responses, classification, extraction. For coding specifically, arena rank and code-specific benchmarks are the best indicators of performance.