Claude Sonnet 4 vs o1

Claude Sonnet 4

Anthropic

Claude Sonnet 4, released by Anthropic in May 2025, is a large language model from the Claude 4 family that delivers a balance of performance and efficiency for coding, reasoning, and analytical tasks. It features a 200K token context window (extendable to 1M tokens in beta), 64K maximum output tokens, native image understanding, and extended thinking support. Sonnet 4 targets development workflows, document analysis, and applications that benefit from the performance characteristics of the Claude 4 generation.

o1

OpenAI

OpenAI o1, released by OpenAI in December 2024, is a reasoning-focused large language model that applies extended chain-of-thought processing before generating responses. It features a 200K token context window and native image understanding, demonstrating strong performance on STEM benchmarks requiring multi-step reasoning. o1 targets mathematics, science, and coding tasks where careful deliberation over the problem produces more accurate outputs than direct generation.