Alex Getmanearly AI signals

Claude Sonnet 4

Anthropic

SightingRelease date unknownUpdated

Signals 1

Specifications

Claude Sonnet 4 is a model from Anthropic, first recorded on 21 Sep 2026; its release date is not established.

Questions

When was Claude Sonnet 4 released?

Its release date is not established. Signal Forge first recorded it on 21 Sep 2026.