Claude 2.1
claude-2.1
2023-11-21 — 2025-07-21 · lived 1 year, 7 months
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.
- Provider
- Anthropic
- Cause of death
- Superseded
- Notice given
- 2025-01-21
- Context
- 200,000 tokens
- Succeeded by
- Claude 3 Opus
“Succeeded by” is this site’s reading of model lineage, not the provider’s official migration guidance.