Founder Elon Musk described Grok 4.5 as an “Opus-class model,” comparing it to Anthropic’s advanced Opus family of large language models. According to Musk, the model offers performance that is roughly comparable to Opus 4.7 but with faster response times and significantly lower costs.

SpaceXAI has priced Grok 4.5 at $2 per million input tokens and $6 per million output tokens. In comparison, Anthropic’s Opus 4.7 costs $5 per million input tokens and $25 per million output tokens. The company also released benchmark results showing that Grok 4.5 performs competitively against leading AI systems, though it does not claim to lead every category.

Meanwhile, OpenAI has shifted its focus toward making AI interactions sound more human. The company introduced two new conversational models, GPT-Live-1 and GPT-Live-1 Mini, designed to support natural voice interactions. Unlike earlier systems that relied on separate speech-to-text, language, and text-to-speech components, the new models use full-duplex technology, enabling them to listen and speak simultaneously.

This allows users to interrupt conversations naturally and makes features such as live translation and extended hands-free interactions possible. OpenAI said the models can also remain silent for long periods while understanding context before responding, making interactions feel more like conversations between humans.

The company is replacing ChatGPT’s existing Advanced Voice Mode with GPT-Live-1 Mini by default, while paid subscribers will gain access to the more capable GPT-Live-1 model. OpenAI also demonstrated the ability of the new voice mode to display information visually during conversations and integrate with the company’s latest reasoning and search models.

According to OpenAI, over 150 million people already use voice-based features in ChatGPT. The company believes voice could eventually become the primary interface for interacting with AI systems, enabling users to complete increasingly complex tasks through natural conversations.