Claude Sonnet 4 vs Skywork-R1V3-38B

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.

Kunlun Tech

Skywork-R1V3-38B, released by Kunlun Tech's Skywork AI team on July 9, 2025, is a 38 billion parameter multimodal reasoning model built on InternVL-38B with reinforcement learning post-training that enhances both visual and textual reasoning. It uses the GRPO algorithm and cold-start fine-tuning to improve reasoning across image and text modalities. Skywork-R1V3-38B targets open-source multimodal reasoning deployments requiring strong performance across vision-language benchmarks.