# Claude Sonnet 4

> The middle of the Claude 4 pair, priced to be the default rather than the decision, and the model that made an agent running for an hour something you would start without first thinking about the bill. It lasted thirteen months and went on the same day as the Opus it had shipped beside — a whole generation buried at once.

2025-05-22 — 2026-06-15 · lived 1 year

This URL is the guided walk — the 3D cemetery, standing at this grave. The written record is at [Claude Sonnet 4's epitaph](https://models.rip/claude-sonnet-4/epitaph).

## Elsewhere

- [The whole cemetery](https://models.rip/)
- [The dataset](https://models.rip/graveyard.json)