What's new in Claude Sonnet 5

Claude Sonnet 5 is a new AI model released by Anthropic with performance similar to their more advanced Opus 4.8 model but at lower advertised prices. However, the model uses a new tokenizer (a system that breaks text into small units for processing) that produces approximately 30% more tokens for the same input text, effectively increasing costs by 1.27x to 1.42x depending on the language, with minimal impact on Simplified Mandarin text.