What happened
Anthropic set Sonnet 5 at low introductory prices. Through August 31, 2026, it costs $2 per million input tokens and $10 per million output tokens. A token is a small chunk of text that models bill by. After that, prices rise to $3 and $15. A new tokenizer can turn the same input into 1.0 to 1.35 times more tokens. A tokenizer is the tool that splits text into tokens.
The context
Model prices are usually quoted per token. A change in how text is split can shift the real bill, even at the same rate.
What this means for you
👤EverydayThis mainly affects developers, but cheaper costs can reach you through the apps you use.
💼At workTeams building on Sonnet 5 pay less now. They should test real usage, since token counts may rise.
🏢BusinessLower headline prices help budgets. The tokenizer change means firms should measure true cost, not just the rate.
🌍The worldOngoing price cuts across labs keep making capable AI cheaper to run.
Ledger entry: Value · Materiality 2 · T1 Primary → ▲ for Anthropic
Sources
- Anthropic, https://www.anthropic.com/news/claude-sonnet-5 T1 Primary