Simon Willison's Weblog
Opus 4.7 tokenizer hikes tokens 1.46x, costs 40% more
Claude Opus 4.7's new tokenizer uses 1.46x more tokens than 4.6 for text (e.g., 7,335 vs 5,039 for system prompt), inflating costs ~40% despite unchanged $5/M input, $25/M output pricing. Images scale with resolution; PDFs only 1.08x.