Sonnet 5 - its updated tokenizer maps the same text to more tokens (roughly 1.0–1.35× depending on content), so cost per task can be higher.
Summary
Anthropic released Claude Sonnet 5 with improved reasoning, tool use, and coding, but its updated tokenizer maps text to more tokens (up to 1.35×), increasing effective cost per task despite the same listed price; introductory pricing applies until August 31, 2026.
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Anthropic released Claude Sonnet 5, a model with performance near Opus 4.8 at lower prices, but featuring a new tokenizer that increases token counts for English and code by ~30%, effectively raising costs.
@rohanpaul_ai: Claude Sonnet 5 is more expensive (around +15%) per task than Opus 4.8 and much more expensive (2X) than Sonnet 4.6, ev…
Claude Sonnet 5 costs more per task than previous models due to higher token usage despite lower per-token price, with discounted pricing until August 2026.
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