o3-pro vs Claude 4.5 Sonnet (thinking)

Detailed comparison of capabilities, features, and performance.

o3-pro

o3-pro

OpenAI
VS
Claude 4.5 Sonnet (thinking)

Claude 4.5 Sonnet (thinking)

Anthropic
Feature o3-pro Claude 4.5 Sonnet (thinking)
AI Lab OpenAI Anthropic
Context Size 200,000 tokens 1,000,000 tokens
Max Output Size 100,000 tokens 64,000 tokens
Frontier Model Yes Yes
Vision Support No Yes
Description o3-pro a version of o3 that uses more compute to think harder and provide reliable answers to challenging problems. The latest Claude 4.5 Sonnet model from Anthropic with maximum reasoning enabled, 200k reasoning tokens in 1M context.

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