Claude Sonnet 4.5

active Active

Claude Sonnet 4.5 is an active Anthropic LLM API model. As of May 24, 2026 it has no announced deprecation or retirement date.

Lifecycle & specs

Provider
Anthropic
API model ID
claude-sonnet-4-5-20250929
Status
active
Released
Sep 29, 2025
Context window
200,000 tokens
Input price
$3.00 / 1M tokens
Output price
$15.00 / 1M tokens
Knowledge cutoff
2025-01-31
Pricing checked
May 22, 2026

Source: official Anthropic documentation ↗ · ✓ verified