Sonnet Catches Up to the Flagship: Claude Sonnet 5 Is Here
Anthropic's new Sonnet is positioned less as a chat assistant and more as something that gets the job done on its own. Claude Sonnet 5 handles planning, tool use, and autonomous operation that used to need larger models — and it checks and corrects its own output without being asked. Anthropic calls it "the most agentic Sonnet model yet."
In brief
- What's new vs Sonnet 4.6: stronger reasoning, tool use, coding, and knowledge work; it finishes multi-step tasks instead of stopping short, and reviews its own output.
- Performance: close to Opus 4.8, at a much lower cost.
- Pricing: introductory through Aug 31, 2026 — $2 per 1M input tokens / $10 per 1M output; standard $3 / $15.
- Access: default on Free and Pro; available to Max, Team, Enterprise; in Claude Code and the Claude Platform; via the API as
claude-sonnet-5. - Safety: lower misalignment rates than Sonnet 4.6; cybersecurity capability deliberately cut relative to Opus models, with cyber safeguards on by default; better at refusing malicious requests and resisting prompt injection.
Our take
What this means for you is simple: your AI budget now stretches further. Multi-step work you'd have paid an expensive model like Opus to do — long reports, code, research — can now go to Sonnet 5 for much less, and to a model that checks its own output. If you work solo or in a small team, automations you'd shelved as "not worth the cost" suddenly pencil out. And the post-Fable 5 emphasis on "safeguards on by default" helps too — it lowers your risk when you're working with client data.
Kaynak: Anthropic