Claude Sonnet 4 vs Phi-3.5-MoE Instruct

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.

Phi-3.5-MoE Instruct

Microsoft

Phi-3.5-MoE-instruct is a sparse mixture-of-experts model from Microsoft's Phi research team, released in August 2024 with 42 billion total parameters across 16 experts and approximately 6.6 billion active parameters per forward pass. The model applies Microsoft's small-data, high-quality training philosophy — developed across earlier Phi generations — to a MoE architecture, targeting reasoning quality comparable to much larger dense models at a fraction of the inference compute. Released under the MIT license, it was notable in the research community for demonstrating that MoE efficiency gains could be realized at smaller total parameter counts than typical large-scale MoE deployments.