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Slow and steady? Anthropic and OpenAI drop new powerful models

Claude Opus 5.5 is the new leader of the Opus family of models, while GPT-6-Sol and Luna are cheaper options compared to the flagship GPT-6-Astra model.

Slow and steady? Anthropic and OpenAI drop new powerful models
Photo by Pietro Mattia / Unsplash

After weeks of debate about the potential harms from continuing to push the boundaries of AI model performance, Anthropic and OpenAI released new models Tuesday that push the boundaries of AI model performance.

Anthropic's Claude Opus 5.5 "is a major step up from Opus 5," the company said in a blog post Tuesday morning, while also acknowledging that it is the first model Anthropic has released since CEO Dario Amodei suggested it was time to "pace the frontier." About an hour later, OpenAI released GPT-6-Sol and GPT-6-Luna, which are less capable than OpenAI's top-of-the-line GPT-6-Astra model but can be run far more cheaply, especially after a price cut.

With the new releases, both companies nodded to the "alignment" issue, which has taken on international importance over the last several weeks as the extent of the OpenAI/Hugging Face hacking incident became clear and researchers from both companies expressed concerns that there's a non-zero chance AI could cause catastrophic outcomes.

"On our automated behavioral audit, the most comprehensive alignment test we run, Opus 5.5 is the strongest-performing model we’ve tested to date," Anthropic said. For OpenAI's part, it said "in our alignment evaluations, both Sol and Luna show improvements over their GPT‑5.6 counterparts, including lower rates of misleading claims about their coding work."

Tale of the tape

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