Claude Sonnet 4.6 vs Seed-1.8

Claude Sonnet 4.6

Anthropic

Claude Sonnet 4.6 is a general-purpose language model from Anthropic, released in February 2026 as an update to the Sonnet 4 line that introduced adaptive thinking — a mode where the model automatically calibrates its reasoning depth based on task complexity rather than requiring manual configuration by the developer. The model accepts text and image inputs and integrates natively with web search and code execution tools, consolidating capabilities that previously required separate toolchain setup into a unified API surface. It became the primary workhorse model in the Claude 4 series for code assistance, agentic pipelines, and retrieval-augmented applications that benefit from built-in web access.

ByteDance

Seed-1.8, developed by ByteDance Seed, is a generalized agentic large language model supporting text and image input, with industry-leading GUI agent capabilities and improvements in multimodal reasoning over its predecessor Seed1.5-VL. It targets information retrieval, code generation, GUI interaction, and complex agentic workflows requiring robust multimodal understanding.