I Measured Claude 4.7's New Tokenizer. Here's What It Costs You.

Anthropic's Claude Opus 4.7 migration guide states the new tokenizer utilizes "roughly 1.0 to 1.35x as many tokens" compared to 4.6. Actual measurements show a higher ratio on technical docs and real CLAUDE.md files. The cost of the new tokenizer was measured using real content and synthetic samples, with the tokenizer showing a consistent increase in token count across different content types.