Tokenizer

Anthropic didn’t raise the price of Claude Opus 4.7. The headline pricing — $5 per million input tokens, $25 per million output tokens — is identical to what developers have been paying. But since Opus 4.7 shipped on April 16, 2026, many teams are paying significantly more anyway. The reason: a new tokenizer that processes the same text into more tokens. How a Tokenizer Change Becomes a Price Hike Tokenizers convert raw text into the numerical tokens that language models actually process. Different tokenizers segment text differently — some are more efficient (fewer tokens per word), others less so. When Anthropic updated the tokenizer in Opus 4.7, they were optimizing for model performance. But as a side effect, the same prompts now consume 1.0 to 1.35x more tokens than they did in previous Claude versions. ...

Claude Opus 4.7 ships with a new tokenizer that can inflate API costs by 1.0–1.35x on identical inputs. Anthropic disclosed this in the release notes — but if you missed it, your bills may have quietly gone up. This guide walks you through auditing your actual token usage and implementing the most effective cost reduction strategies available today. Who this is for: Teams running OpenClaw agents with Claude Opus backends, or anyone using the Anthropic API directly with Opus 4.7. ...