Claude Opus 5 arrives with near Fable performance at half the price

Claude Opus 5 arrives with near Fable performance at half the price">

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To the surprise of no one, Anthropic has released Claude Opus 5 . After releasing the controversial Mythos 5 and Fable 5 last month and Sonnet 5 on July 1 , it was inevitable that Opus would be bumped from 4.8 to 5. That's happening today.

I've been impressed with Opus 4.8. I've been using it for a number of large coding projects, and it's handled them quite well. But based on limited user reports, it's likely that Claude Code will get another big boost.

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I'm not the only one impressed with Opus, based on the accolades included in Anthropic's announcement.

Cristian Rivera, software engineer at Stripe, says, "Opus 5 is a clear generational step up from Opus 4.8. Over one weekend, I gave it a chief-of-staff role over my dev environments: it built its own monitor, drove each box, and pulled me in only for the judgment calls."

Harvey creates AI legal tools. According to Niko Grupen, Harvey's head of applied research, "Claude Opus 5 is a clear step up in performance on legal agent work compared to prior Opus models, and we saw the biggest gains in practice areas like corporate governance and arbitration."

He adds: "We were also impressed with Opus 5's ability to maintain quality at lower reasoning levels, achieving similar performance while generating 26% fewer tokens on average compared to Opus 4.8 at max reasoning."

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Token use isn't just a measure of cost. It's also a measure of how much stress the AI is handling while it's working on complex issues. There have been a number of times, even with Opus 4.8's million-token context window, that my Claude Code has requested a recess and to take time to nap.

Using fewer tokens for the same work means it might go farther in a given session. That would be helpful.

Anthropic says that "Opus 5 comes close to the capabilities of Claude Fable 5 in many domains at half the price." The company reports that it has the strongest knowledge work performance of any model it's released, and delivers substantial gains on complex coding. These two would go directly to improve work in both Claude Cowork and Claude Code.