Anthropic has introduced Claude Opus 4 and Claude Sonnet 4, its latest generation of hybrid-reasoning AI models optimized for coding tasks and solving complex problems. 

Claude Opus 4 is Anthropic’s most powerful AI model to date, according to the company’s announcement, and capable of working continuously on long-running tasks for “several hours.” In customer tests, Anthropic said that Opus 4 performed autonomously for seven hours, significantly expanding the possibilities for AI agents. The company also described its new flagship as the “best coding model in the world,” with Anthropic’s benchmarks showing that Opus 4 outperformed Google’s Gemini 2.5 Pro, OpenAI’s o3 reasoning, and GPT-4.1 models in coding tasks and using “tools” like web search.

Claude Sonnet 4 is a more affordable and efficiency-focused model that’s better suited to general tasks, which supersedes the 3.7 Sonnet model released in February. Anthropic says Sonnet 4 delivers “superior coding and reasoning” while providing more precise responses. The company adds that both models are 65 percent less likely to take shortcuts and loopholes to complete tasks compared to 3.7 Sonnet and they’re better at storing key information for long-term tasks when developers provide Claude with local file access.

A new feature introduced for both Claude 4 models is “thinking summaries,” which condenses the chatbots’ reasoning process into easily understandable insights. An “extended thinking” feature is also launching in beta that allows users to switch the models between modes for reasoning or using tools to improve the performance and accuracy of responses.

Claude Opus 4 and Sonnet 4 are available on the Anthropic API, Amazon Bedrock, and Google Cloud’s Vertex AI platform, and both models are included in paid Claude plans alongside the extended thinking beta feature. Free users can only access Claude Sonnet 4 for now.

In addition to the new models, Anthropic’s Claude Code agentic command-line tool is now generally available following its limited preview in February. Anthropic also says it’s shifting to provide “more frequent model updates,” as the company tries to keep up with competition from OpenAI, Google, and Meta.