Claude Sonnet 4 vs o3

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.

o3

OpenAI

OpenAI o3, released by OpenAI in April 2025, is a large reasoning model that applies extended chain-of-thought processing to deliver improved performance on complex math, science, and coding tasks. It features a 200K token context window and native image understanding, with demonstrated strong results on mathematics and software engineering benchmarks. o3 targets demanding analytical and engineering tasks where deliberate, multi-step reasoning produces significantly better outcomes than direct generation.