Anthropic and OpenAI Announce New AI Models with Improved Performance and Lower Costs

Anthropic released Opus 5.5 with Fable-level performance at lower prices, while OpenAI launched GPT-6 Sol and Luna models with reduced costs and errors.

According to the Last Week in AI Podcast #258, Anthropic has released Opus 5.5, a new model that delivers Fable-level performance while offering lower pricing compared to previous versions. The announcement represents a significant update to Anthropic’s Claude model lineup.

In parallel developments, OpenAI has launched two new models as part of its GPT-6 series, named Sol and Luna. According to the podcast, these models are designed to offer lower costs and make fewer mistakes compared to earlier iterations. The dual release suggests OpenAI may be positioning different models for varying use cases or performance requirements.

The podcast also mentioned other AI developments including Muse, DeepSeek-V4.1-Flash, and Xi, though specific details about these releases were not provided in the source material. The timing of these announcements from both Anthropic and OpenAI indicates continued competition in the AI model market, with both companies focusing on improving performance while reducing costs for users.