# Claude 2.1

> It doubled the window to two hundred thousand tokens, and within a fortnight someone had hidden a single sentence in the middle of one and published what came back. Anthropic replied with a post showing that adding one line — "Here is the most relevant sentence in the context:" — moved recall from 27% to 98%. The headline was the window; the durable lesson was about how you ask.

2023-11-21 — 2025-07-21 · lived 1 year, 7 months

## The record

- Provider: Anthropic
- Model id: `claude-2.1`
- Cause of death: Superseded
- Notice given: 2025-01-21
- Context window: 200,000 tokens
- Succeeded by: [Claude 3 Opus](https://models.rip/claude-3-opus/epitaph) (this archive's reading of lineage, not the provider's migration guidance)

## Sources

- https://platform.claude.com/docs/en/about-claude/model-deprecations
- https://www.anthropic.com/news/claude-2-1
- https://claude.com/blog/claude-2-1-prompting

## Elsewhere

- [Stand at this grave](https://models.rip/claude-2.1)
- [The Anthropic plot](https://models.rip/anthropic)
- [The whole cemetery](https://models.rip/)