Anthropic and OpenAI Drop New High-Efficiency Models

Both OpenAI and Anthropic dropped new models on Tuesday, each highlighting enhanced speed while being cheaper overall compared to predecessors. 

Anthropic said its new model, Opus 5.5, matches the capabilities of Fable 5.1 but cuts the cost by nearly 40% compared to Opus 5. OpenAI’s models, GPT-6 Sol and GPT-6 Luna, are follow-up models from the previous 5.6 versions that were released back in July of this year, but are hot on the heels of ChatGPT Astra, which was released in early September. 

Below, we’ll show you all the details for the new models.

GPT-6 Sol and Luna 

The latest models from OpenAI are designed to make the power of GPT-6 Astra more accessible at lower budgets while providing higher usage limits for business and developer workflows. Since GPT-6 Sol and Luna are trained with similar methods as Astra, you’ll still reap the benefits you’d get with the more powerful model, including enhancements in coding and computer use, though OpenAI still says that GPT-6 Astra is the “world’s best model” for computer use. 

OpenAI said the latest ChatGPT models also put a big focus on factuality, or the usefulness of the answers it provides you after your prompt. OpenAI says its latest models make less than half the mistakes of their predecessors.