2 min readJul 25, 2026 09:55 AM IST
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.
Story continues below this ad
Open-weight models allow users to download, run and customise the virtual brains of an AI, unlike proprietary models.