// 9TO5MAC — MOBILE & WEB
Anthropic upgrades Claude with new Opus 5.5 model, details here
Anthropic has released its latest AI model with Claude Opus 5.5. The new version arrives about two months after the previous Opus model upgrade, matching Anthropic’s previous upgrade cadence.
Anthropic currently offers a few AI models under the Claude umbrella.
The three main models are Haiku (smallest and cheapest), Sonnet (medium size and price), and Opus (largest and most expensive of the three).
There’s also Fable/Mythos, which is even more capable and costly, which represents Anthropic’s highest tier.
Opus 5.5 is here! 🎉 It's honestly such a nice model to work with. Feels like Fable, but ~30% faster and ~40% cheaper per task than Opus 5. Go try it out! pic.twitter.com/zwo83sbgez
Today’s release upgrades Claude’s Opus model from version 5 to version 5.5.
“Opus 5.5 is our first model since we called for pacing the frontier,” Anthropic says. “As with previous models, it was tested by external evaluators before release, including METR and Frontier Design. On our most comprehensive alignment test, it achieves the strongest score to date.”
Here’s what Anthropic says about Opus 5.5 performance:
Opus 5.5 is a major step up from Opus 5. It’s the new leading model, and early testers saw large jumps in performance on their most complex work. One tester completed a 680,000-line code migration in less than a day—work that would have taken an engineering team weeks. It’s good at finding and fixing inefficiencies in software: when we asked it to cut load times across every page of a web app, Opus 5.5 succeeded 39 of 40 times, while Opus 5 made smaller improvements that also altered the app’s behavior. A different tester had several Claude models build a game from a single prompt; Opus 5.5 scored higher than any other model on the strength of its graphics and polish.
When it comes to coding specifically, here’s what Anthropic says: