Anthropic launches Claude Sonnet 5 with Opus

Anthropic has launched Claude Sonnet 5, a model that brings capabilities previously exclusive to the Opus series at a more affordable price point.

Sonnet 5 is available with introductory API pricing of $2 per million input tokens and $10 per million output tokens through August 31, 2026. After that, standard pricing will be $3 per million input tokens and $15 per million output tokens. The model is now accessible to Free, Pro, and Max subscribers.

What makes Sonnet 5 different from previous models

Anthropic describes Sonnet 5 as the most agentic Sonnet model yet, featuring capabilities that were previously mostly limited to Opus 4.8, including multi-step planning, use of tools such as browsers and terminals, self-verification of its output without explicit prompts, and improved agentic search across large codebases.

These enhancements target users who rely on Claude for coding, research, automation, and document work, while Sonnet 4.6 was generally seen as weaker in planning and understanding large codebases, but this version appears to significantly close that gap.

The pricing positions the new model as a budget-friendly alternative to Opus 4.8. By comparison, the higher-tier model costs $5 per million tokens for input and $25 for output. At standard pricing, it is roughly 60% less expensive than the Opus model.

Benchmark tests from BrowseComp and OSWorld-Verified support the performance claims, indicating that the new model performs noticeably closer to the higher-tier model than Sonnet 4.6 did. Users can choose between the two based on their preferences for cost savings or maximum performance.

Why Fable 5 and Mythos 5 are returning

The release of this model comes as the company restores access to Claude Fable 5 and Mythos 5. These models had been offline for two and a half weeks following a US government order restricting foreign national access, citing national security concerns. Anthropic announced on X that the Department of Commerce has lifted export controls on both models. Commerce Secretary Howard Lutnick said the government had worked closely with the firm over the past two weeks to assess and approve Fable 5 and to support US leadership in AI.

A letter from Lutnick to the company, cited by multiple outlets, noted that the firm had coordinated with the government to proactively identify and address security risks related to the models. It has committed to inform the government if it detects any malicious activities involving the models.

Lutnick’s letter also warned that the Trump administration reserves the right to reimpose restrictions in the future if circumstances change or if the company fails to meet its commitments.

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White House Chief of Staff Susie Wiles expressed gratitude to industries working closely with the White House to implement the President’s executive order on promoting advanced AI innovation and security. She noted ongoing efforts around model access, guardrails, testing, and security, emphasizing that the priority remains deploying the best technology as quickly as possible.

Which Claude model users should consider

Anthropic’s paid tiers give users immediate access to Sonnet 5 through the Claude app, Claude Code, and the Anthropic API. Free-tier users can also access the model.

For those temporarily locked out of Fable 5 and Mythos 5 during the two-week suspension, access is being gradually restored starting Wednesday. Pro, Max, and Enterprise plan users should see the models reappear in their selection menus.

This version offers the best cost-performance balance for most tasks involving agency and coding, while the Opus model provides maximum performance for the most demanding tasks.

Fable 5 shares architecture with Mythos and includes safety guardrails, available at usage-based pricing after the free period ending June 22. Mythos 5 remains restricted to vetted partners, including government cyberdefenders and certain life sciences researchers.

The ongoing developments demonstrate the company’s efforts to balance expanding its business with managing government regulations, as the launch of Fable 5 in June, its suspension, and now its reinstatement alongside a more affordable Sonnet release show how the firm is refining its product lineup while dealing with increasingly complex rules for advanced AI models.

The release of this model also strengthens the company’s position against OpenAI, which recently delayed the public rollout of GPT-5.6 at the request of the US government, limiting access to selected partners, while Anthropic now offers a wider range of accessible models for developers and users than OpenAI in the near future.

Sonnet 5 is available now.