How to try Claude Opus 4.8, the 'honest' Anthropic AI

Anthropic isn't ready to let regular users look at its supposedly super-powerful Claude Mythos AI model just yet. But the AI company has just released an upgrade to its flagship product, Claude Opus — now in its 4.8 version.

"It builds on Opus 4.7 with improvements across benchmarks, and is a more effective collaborator," Anthropic promised in a press release Thursday. Indeed, the benchmark numbers, below, show very minor improvements across the board.

One major improvement, allegedly, is in the area of hallucinations. Claude Opus 4.8 won't lie to users as much. "Early testers report that Opus 4.8 is more likely to flag uncertainties about its work and less likely to make unsupported claims," Anthropic said, touting the model's "honesty."

Claude Opus 4.8 has 'better judgment'

"Claude Opus 4.8 has noticeably better judgment," an engineer at Shopify, Tom Pritchard, told Anthropic. The coding version of the model "asks the right questions, catches its own mistakes, and pushes back when a plan isn't sound."

Given the increasing number of horror stories about AI agents deleting entire corporate databases, that promise may be music to the ears of vibe coders everywhere.

To please power users, Anthropic is offering a significant discount on "fast mode," where Claude will work at 2.5 times regular speed. Fast mode "is now three times cheaper than it was for previous models," the company said.

Users on Reddit weren't buying it, however. Many feared a loss of access to a more popular model, Claude Opus 4.6. "Nobody trusts the benchmark charts," wrote one redditor in summary, noting that Opus 4.7 also seemed to have some pretty good numbers when it was released.

Whether or not we can trust the benchmarks — and to be clear, Mashable hasn't independently verified these numbers — here's what Anthropic is claiming.

Claude Opus 4.8 is available now via Anthropic's website, Claude.AI, as well as via the Claude API, plus Anthropic partners like Microsoft Foundry.

The new model is priced exactly the same as its predecessors, which is to say models going all the way back to Claude Opus 4.5. All of them will cost you $5 per million input tokens and $25 per million output tokens.

Given that Anthropic is promising Claude Mythos within a matter of weeks, however, you may want to hang back and wait to see whether that model can be even more "honest" about its hallucinations.

Topics Artificial Intelligence Anthropic

Chris is a veteran tech, entertainment and culture journalist, author of 'How Star Wars Conquered the Universe,' and co-host of the Doctor Who podcast 'Pull to Open.' Hailing from the U.K., Chris got his start as a sub editor on national newspapers. He moved to the U.S. in 1996, and became senior news writer for Time.com a year later. In 2000, he was named San Francisco bureau chief for Time magazine. He has served as senior editor for Business 2.0, and West Coast editor for Fortune Small Business and Fast Company. Chris is a graduate of Merton College, Oxford and the Columbia University Graduate School of Journalism. He is also a long-time volunteer at 826 Valencia, the nationwide after-school program co-founded by author Dave Eggers. His book on the history of Star Wars is an international bestseller and has been translated into 11 languages.