The model that quietly beat GPT-4 on coding. Anthropic's 3.5 Sonnet.
Claude 3.5 Sonnet was the release that made engineers reconsider their default. It led coding and agentic benchmarks, wrote cleaner diffs than its peers, and reasoned through multi-file changes without falling apart. It remains a workhorse inside Claude, Cursor, and a dozen other tools.
Who it's for: Developers, analysts, and writers who want a fast, capable model that is strong at code and long documents. The safe daily-driver choice.
Leads SWE-bench-style tasks; strong at real repos, not just toy snippets.
Handles long reports and books with coherent recall.
Reads charts, screenshots, and whiteboard photos.
Fast enough for interactive editing and chat.
Claude 3.5 Sonnet is the model most people should keep as a default in 2026. It is fast, cheap (free), and especially good at code and documents. Reach for a newer flagship only when you need the absolute cutting edge.