According to Anthropic, Sonnet 4.6 significantly improves performance in coding, design, data handling and complex office tasks. The company says tasks previously reserved for the high-end Opus model are now supported by Sonnet, lowering the barrier to advanced capabilities. The announcement comes just twelve days after that of Claude Opus 4.6, highlighting a push for speed to meet competition from Google and OpenAI.

This technical acceleration is also fuelling tension in the markets. Investors fear a challenge to traditional software business models, against a backdrop of a sharp correction in SaaS stocks. Claude Sonnet 4.6, which includes markedly strengthened coding skills, could add to that pressure by offering more powerful solutions at a lower cost.