Anthropic's new Opus 4.7 tokenizer inflates costs by up to 47% despite maintaining the same per-token pricing as its predecessor.

Opus 4.7 uses a new tokenizer that converts the same text into up to 47% more tokens than Opus 4.6

While per-token pricing remains flat between the two models, actual request costs are significantly higher due to increased token consumption

Claude Code users are seeing measurable cost increases in practice from this tokenizer change

The price increase effectively contradicts Anthropic's stated flat pricing structure between model generations