Claude Sonnet 4.5 vs Skywork-R1V3-38B

Claude Sonnet 4.5

Anthropic

Claude Sonnet 4.5, released by Anthropic in September 2025, is a large language model from the Claude 4.5 family that balances response quality and efficiency for coding, agentic tasks, and analytical work. 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 4.5 targets use cases that require a balance of throughput and reasoning depth, including code generation, data analysis, and multi-step agentic pipelines.

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.