Anthropic rolls out Opus 5 AI model in efficiency upgrade

Anthropic on Friday launched Opus 5, its ‌latest AI ⁠model that ⁠the startup says nears the capabilities of its more powerful cousin Fable ​5 at half the price.

The San Francisco-based lab said the new Claude AI ​model was well suited for daily office and computer programming tasks.

In an interview with Reuters, Anthropic product leader Dianne Penn said ​the release, more efficient than May's ⁠Opus 4.8, reflected ‌a rapid pace of development.


"We're building and ​continue to ​consistently deliver frontier intelligence and bring that as ⁠accessibly as possible with every model generation," said Penn.

In ​testing, Opus 5 was less capable of ​exploiting cyber vulnerabilities than Anthropic's top-shelf AI, so its related safeguards are less restrictive than Fable 5's. Opus 5 was also less susceptible to being tricked into misuse than Anthropic's other current models, the startup said.

Released in June, Anthropic's Fable 5 ‌was temporarily unavailable following U.S. concerns that its capabilities could be diverted to foreign military intelligence.

Users should pick ​Opus 5 ​for value and ⁠Fable 5 for "days-long, very autonomous projects," Penn said. Asked about the Kimi K3 "open" model from China-based Moonshot, which the U.S. accused of freeloading ​off Anthropic, Penn said it "remains to be seen" how open-weight models generally perform on complicated real-world projects that users ask Claude to tackle.

Open-weight models allow users to download, run and customise the virtual brains of an AI, unlike proprietary models.