Claude Sonnet 5 launched with introductory pricing of $2.00 per million input tokens and $10.00 per million output tokens. Anthropic had originally scheduled an increase to $3.00/$15.00 for September 1, 2026. According to Anthropic's own Claude Platform pricing documentation, that increase will not occur, and $2/$10 is now the standard, permanent rate.
This keeps Sonnet 5 priced identically to its input rate on release, which matters if you were budgeting around an expected 50% cost increase for any Sonnet 5-based workload. That increase is no longer coming.
For comparison, current Anthropic pricing (per million tokens) runs Claude Haiku 4.5 at $1/$5, Claude Sonnet 5 at $2/$10, Claude Opus 5 at $5/$25, and Claude Fable 5.1 at $10/$50.
Our AI API Cost Calculator and the underlying pricing data have been verified against this update. No changes are needed to your existing Sonnet 5 cost estimates.