Claude Sonnet 4.5 vs GPT-4

Compare Claude Sonnet 4.5 by Anthropic against GPT-4 by OpenAI, context windows of 200K vs 8K, tested across 21 shared challenges. Updated April 2026.

Which is better, Claude Sonnet 4.5 or GPT-4?

Claude Sonnet 4.5 and GPT-4 are both competitive models. Claude Sonnet 4.5 costs $3/M input tokens vs $30/M for GPT-4. Context windows: 200K vs 8K tokens. Compare their real outputs side by side below.

Key Differences Between Claude Sonnet 4.5 and GPT-4

Claude Sonnet 4.5 is made by anthropic while GPT-4 is from openai. Claude Sonnet 4.5 has a 200K token context window compared to GPT-4's 8K. On pricing, Claude Sonnet 4.5 costs $3/M input tokens vs $30/M for GPT-4.

Our Verdict
Claude Sonnet 4.5
Claude Sonnet 4.5
GPT-4
GPT-4

No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.

Claude Sonnet 4.5 is 4.0x cheaper per token — worth considering if cost matters.

Too close to call
Writing DNA

Style Comparison

Similarity
86%

Claude Sonnet 4.5 uses 45.2x more emoji

Claude Sonnet 4.5
GPT-4
64%Vocabulary59%
94wSentence Length18w
0.48Hedging1.10
4.9Bold0.8
8.0Lists2.5
0.45Emoji0.00
1.91Headings0.00
0.07Transitions0.45
Based on 20 + 15 text responses
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Claude Sonnet 4.5GPT-4

279 AI models invented the same fake scientist.

We read every word. 250 models. 2.14 million words. This is what we found.

AI Hallucination Index 2026
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