Claude 3 Sonnet vs GPT-5 Pro

Compare Claude 3 Sonnet by Anthropic against GPT-5 Pro by OpenAI, tested across 10 shared challenges. Updated April 2026.

Which is better, Claude 3 Sonnet or GPT-5 Pro?

Claude 3 Sonnet and GPT-5 Pro are both competitive models. Claude 3 Sonnet costs $3/M input tokens vs $15/M for GPT-5 Pro. Compare their real outputs side by side below.

Key Differences Between Claude 3 Sonnet and GPT-5 Pro

Claude 3 Sonnet is made by anthropic while GPT-5 Pro is from openai. On pricing, Claude 3 Sonnet costs $3/M input tokens vs $15/M for GPT-5 Pro.

Our Verdict
GPT-5 Pro
GPT-5 Pro
Claude 3 Sonnet
Claude 3 SonnetRunner-up

No community votes yet. On paper, GPT-5 Pro has the edge — bigger model tier, newer, bigger context window.

Claude 3 Sonnet is 8.0x cheaper per token — worth considering if cost matters.

Too close to call
Writing DNA

Style Comparison

Similarity
99%

Claude 3 Sonnet uses 37.6x more transitions

Claude 3 Sonnet
GPT-5 Pro
48%Vocabulary65%
14wSentence Length15w
0.32Hedging0.32
0.0Bold0.0
3.6Lists2.9
0.00Emoji0.00
0.00Headings0.00
0.38Transitions0.01
Based on 4 + 11 text responses
vs

Ask them anything yourself

Claude 3 SonnetGPT-5 Pro

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
Free preview13 of 58 slides
FAQ

Common questions