Anthropic Launches New Claude 4 Gen AI Models

The latest versions of Anthropic's Claude generative AI models made their debut Thursday, including a heavier-duty model built specifically for coding and complex tasks.

Anthropic launched the new Claude 4 Opus and Claude 4 Sonnet models during its Code with Claude developer conference, and executives said the new tools mark a significant step forward in terms of reasoning and deep thinking skills.

The company launched the prior model, Claude 3.7 Sonnet, in February. Since then, competing AI developers have also upped their game. OpenAI released GPT-4.1 in April, with an emphasis on an expanded context window, along with the new o3 reasoning model family. Google followed in early May with an updated version of Gemini 2.5 Pro that it said is better at coding.

Claude 4 Opus is a larger, more resource-intensive model built to handle particularly difficult challenges. Anthropic CEO Dario Amodei said test users have seen it quickly handle tasks that might have taken a person several hours to complete. 

"In many ways, as we're often finding with large models, the benchmarks don't fully do justice to it," he said during the keynote event.

Anthropic said Claude 4 took notes on how to navigate while playing Pokemon.

Anthropic

Claude 4 Sonnet is a leaner model, with improvements built on Anthropic's Claude 3.7 Sonnet model. The 3.7 model often had problems with overeagerness and sometimes did more than the user asked it to do, Amodei said. While it's a less resource-intensive model, it still performs well, he said. 

"It actually does just as well as Opus on some of the coding benchmarks, but I think it's leaner and more narrowly focused," Amodei said.

Anthropic said the models have a new capability, still being beta tested, in which they can use tools like web searches while engaged in extended reasoning. The models can alternate between reasoning and using tools to get better responses to complex queries.

The models both offer near-instant response modes and extended thinking modes. 

All of the paid plans offer both Opus and Sonnet models, while the free plan just has the Sonnet model.