Introducing Claude Sonnet 5 \ Anthropic<br>Try Claude

Product<br>Introducing Claude Sonnet 5<br>Jun 30, 2026

Claude Sonnet 5 is built to be the most agentic Sonnet model yet. It can make plans, use tools like browsers and terminals, and run autonomously at a level that, just a few months ago, required larger and more expensive models.<br>For many developers, the agentic AI era began with Sonnet-class models: Claude Sonnet 3.5, 3.6, and 3.7 were the first models that showed impressive skills in coding and tool use. More recently, though, the clearest gains in agentic capabilities have been in our Opus-class models.<br>Sonnet 5 narrows the gap: its performance is close to that of Opus 4.8, but at lower prices. It’s a substantial improvement over its predecessor, Sonnet 4.6, on important aspects of agentic performance like reasoning, tool use, coding, and knowledge work:<br>Scores for Sonnet 5 on a variety of evaluations compared to those of Sonnet 4.6 and Opus 4.8 (a more generally capable model, for reference). The Claude Sonnet 5 System Card reports a broader set of evaluations in detail.<br>Our safety assessments found that Sonnet 5 shows an overall lower rate of undesirable behaviors than Sonnet 4.6, and is generally safer to use in agentic contexts. Evaluations also show that it has a much lower ability to perform cybersecurity tasks than our current Opus models.<br>From today, Claude Sonnet 5 is available across all plans: it is the default model for Free and Pro plans, and is available to Max, Team, and Enterprise users. It’s also available in Claude Code and on the Claude Platform, where it launches with introductory pricing of $2 per million input tokens and $10 per million output tokens through August 31, 2026, after which it will be priced at $3 per million input tokens and $15 per million output tokens. Developers can use claude-sonnet-5 via the Claude API.<br>Working with Claude Sonnet 5<br>The charts below compare the performance of Sonnet 5 with Sonnet 4.6 and Opus 4.8 at different effort levels on the agentic search evaluation BrowseComp and the computer use evaluation OSWorld-Verified. Sonnet 5 (orange line) is a strict improvement over Sonnet 4.6 (gray line). Opus 4.8 (yellow line) is still the model of choice for higher accuracy on these tasks, but Sonnet 5 provides developers with lower-priced options that are of much higher quality than what was previously available. Between Sonnet 5 and Opus 4.8, users can adjust the effort level to find the right balance of cost and performance.<br>Agentic searchAgentic computer use<br>Cost-performance curves at different effort levels. The previous best Sonnet model (Sonnet 4.6) fell well short of Opus 4.8. Now Sonnet 5 and Opus 4.8 cover a single range, with Sonnet 5 offering impressive capabilities at a lower cost and Opus 4.8 offering greater accuracy at a higher price. The charts show Sonnet 5 priced at $3 per million input tokens and $15 per million output tokens. Furthermore, with the introductory launch pricing through August 31 ($2/MTok input and $10/MTok output), the effective cost of Sonnet 5 is even lower than shown here. Opus 4.8 is priced at $5/MTok input and $25/MTok output. xhigh = extra high effort level.<br>Cost-performance curves at different effort levels. The previous best Sonnet model (Sonnet 4.6) fell well short of Opus 4.8. Now Sonnet 5 and Opus 4.8 cover a single range, with Sonnet 5 offering impressive capabilities at a lower cost and Opus 4.8 offering greater accuracy at a higher price. The charts show Sonnet 5 priced at $3 per million input tokens and $15 per million output tokens. Furthermore, with the introductory launch pricing through August 31 ($2/MTok input and $10/MTok output), the effective cost of Sonnet 5 is even lower than shown here. Opus 4.8 is priced at $5/MTok input and $25/MTok output. xhigh = extra high effort level.

Feedback from our early access partners has been consistent: Sonnet 5 is much more agentic than its predecessors. Testers described how it finishes complex tasks where previous Sonnet models would stop short, how it checks its own output without explicitly being asked, and how it does all this agentic work at an attractive price point:

Claude Sonnet 5 gives our agents a strong execution layer for multi-step software engineering work. It handles sustained coding, tool use, and debugging well across messy technical contexts, and has been especially useful for workflows where follow-through and technical grounding matter.

We handed Claude Sonnet 5 a two-part job—update Salesforce account tiers, send a launch announcement to enterprise contacts—and it finished end to end. That used to stall halfway. For day-to-day automation, it’s a no-brainer

Claude Sonnet 5 gets more done with less. Same output quality, fewer steps to get there. It refuses unsafe requests cleanly and consistently, too. At Lovable, we’re putting powerful tools in the hands of millions of builders. A model that knows when to say no is just as important as one that...