Claude Sonnet 4.6 Is Now Available in Puter.js

Puter.js now supports Claude Sonnet 4.6, Anthropic's most capable Sonnet model—delivering near-Opus-level performance in coding, agentic tasks, and long-context reasoning at Sonnet pricing.

What is Claude Sonnet 4.6?

Claude Sonnet 4.6 is Anthropic's latest Sonnet-class model, released on February 17, 2026. It is the user's preferred model over Sonnet 4.5 in roughly 70% of the time in head-to-head comparisons.

Key highlights:

• Near-Opus performance — scores 79.6% on SWE-bench Verified, nearly matching Opus 4.6's 80.8%, and actually outperforms it on office task and financial analysis benchmarks
• 1 million token context window (beta) — process entire codebases, lengthy contracts, and dozens of research papers in a single request
• 70% more token-efficient — uses significantly fewer tokens than Sonnet 4.5 while achieving 38% higher accuracy on filesystem benchmarks
• Adaptive and extended thinking — functions as both a standard model and a reasoning model, with fine-grained control over thinking effort
• Improved coding — better instruction following, fewer hallucinations, and reduced overengineering compared to previous Sonnet models
• Enhanced computer use — near-fivefold improvement on OSWorld benchmarks, achieving 72.5% accuracy, essentially tied with Opus 4.6

Examples

Code Generation

puter.ai.chat("Write a React hook that debounces API calls with configurable delay and cancellation support",
  { model: 'claude-sonnet-4-6' }
);

Long-Context Analysis

puter.ai.chat([
  { role: "user", content: largeDocument + "\n\nSummarize the key findings and flag any inconsistencies across sections." }
], { model: 'claude-sonnet-4-6' });

Streaming

const response = await puter.ai.chat(
  "Explain the architectural differences between microservices and monolithic applications with real-world examples",
  { model: 'claude-sonnet-4-6', stream: true }
);

for await (const part of response) {
  puter.print(part?.text);
}

Get Started Now

Just add one script tag to your HTML:

<script src="https://js.puter.com/v2/"></script>

No API keys and no infrastructure setup. Start building with Claude Sonnet 4.6 immediately.

Learn more:

• Free, Unlimited Claude API
• Puter.js AI Documentation