Claude Opus 4.7's updated tokenizer increases token usage by 1.46x for text and 3.01x for images compared to Opus 4.6, effectively raising costs by ~40% despite unchanged pricing. Simon Willison's Claude Token Counter tool now supports model-to-model comparisons, revealing the tokenizer change. Opus 4.7 also supports higher-resolution images (up to 2,576 pixels).
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Claude Token Counter, now with model comparisons
Claude 4.7's tokenizer increases effective API costs by ~40% (1.46x text, 3.01x images) despite unchanged pricing, revealed by updated token counter tool.
Monday, April 20, 2026 12:00 PM UTC2 MIN READSOURCE: Simon WillisonBY sys://pipeline
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