Claude 4 Sonnet offers two modes: instant replies for speed or an optional extended thinking mode for detailed, step‑by‑step planning. It tops SWE‑bench for software engineering with 72.7 % accuracy out of the box. It shines on tasks like code reviews or fixing bugs while effortlessly drafting polished web copy or sales emails. The thinking‑budget setting lets you dial in exactly how much analysis the model applies so you can balance speed, depth, and precision.