Apple is significantly upgrading Siri using large language models (LLMs), internally testing models with up to 150 billion parameters. Benchmarks suggest the largest model rivals ChatGPT's quality, though concerns remain about inaccuracies. A new chatbot, "Knowledge," accessing internet data, is also under development but faces delays. While a launch date is unclear, Google's Gemini and potentially Perplexity's AI will be integrated into iOS 26 as Siri alternatives.