Model Tracker
Claude 2.1
Claude 2.1 is an AI model made by Anthropic. Anthropic released it on 21 November 2023. It is retired. Anthropic retired it on 21 July 2025.
Claude 2.1 is an AI model made by Anthropic. Anthropic released it on 21 November 2023. It is retired. Anthropic retired it on 21 July 2025. It takes text and returns text. Its context window is 200,000 tokens. Its knowledge cutoff is 2023.
- Released
- 21 November 2023 — www.anthropic.com, read 16 October 2026
- Status
- Retired — platform.claude.com, read 16 October 2026
- Retired
- 21 July 2025 — platform.claude.com, read 16 October 2026
- Takes
- Text — www-cdn.anthropic.com, read 16 October 2026
- Returns
- Text — www-cdn.anthropic.com, read 16 October 2026
- Open weights
- Not confirmed: The maker's pages reviewed do not state whether Claude 2.1's weights are open or downloadable.
- Licence
- Not confirmed: The maker's pages reviewed do not name a licence for Claude 2.1's weights.
- Context window
- 200,000 tokens — www.anthropic.com, read 16 October 2026
- Longest answer
- Not confirmed: The model card gives an output limit for Claude 2, but the pages reviewed do not print a standard maximum output limit specifically for Claude 2.1.
- Knowledge cutoff
- 2023 — www-cdn.anthropic.com, read 16 October 2026
- API price, input
- Not confirmed: The archived November 2023 pricing sheet lists Claude 2.1 input pricing, but the current pricing page does not confirm a standard API price for this retired model.
- API price, output
- Not confirmed: The archived November 2023 pricing sheet lists Claude 2.1 output pricing, but the current pricing page does not confirm a standard API price for this retired model.
- Where
- Not confirmed: The launch announcement names the API and claude.ai as availability at launch, while the deprecation page confirms retirement on Anthropic-operated platforms; the pages reviewed do not confirm a complete current availability list across the register's venues.
- Parameters
- Not confirmed: The maker's pages reviewed do not publish Claude 2.1's parameter count.
- Model card
- https://www-cdn.anthropic.com/5c49cc247484cecf107c699baf29250302e5da70/claude-2-model-card.pdf — www-cdn.anthropic.com, read 16 October 2026
Benchmarks
Measured by others, not by the maker: each score with the name the measurer gives the model and the setting it ran, its day and its licence.
Epoch AI
- Epoch Capabilities Index, Claude 2.1: 119.3 (112.2–121.9), as of 19 October 2026
- GPQA Diamond, claude-2.1: 33.0% (± 2.3), run 27 January 2025
- OTIS Mock AIME 2024–2025, claude-2.1: 1.9% (± 1.0), run 7 March 2025
Epoch AI, ‘Capabilities & benchmarking’, epoch.ai/benchmarks, CC BY 4.0: Epoch AI’s own runs and its Capabilities Index. Data · CC BY 4.0
Questions
When was Claude 2.1 released?
Anthropic released Claude 2.1 on 21 November 2023.
Is Claude 2.1 still available?
No: Anthropic retired Claude 2.1 on 21 July 2025.
What is the context window of Claude 2.1?
The context window of Claude 2.1 is 200,000 tokens, as Anthropic prints it.
What does Claude 2.1 take and return?
Claude 2.1 takes text and returns text.
What is the knowledge cutoff of Claude 2.1?
The knowledge cutoff of Claude 2.1 is 2023.
More from Anthropic
- Claude 1.0
- Claude 1.1
- Claude 1.2
- Claude 1.3
- Claude 2
- Claude 3 Haiku
- Claude 3 Opus
- Claude 3 Sonnet
- Claude 3.5 Haiku
- Claude Fable 5
- Claude Fable 5.1
- Claude Haiku 4.5
- Claude Haiku 5.5
- Claude Instant 1.0
- Claude Instant 1.1
- Claude Instant 1.2
- Claude Mythos Preview
- Claude Opus 4.1
- Claude Opus 4.5
- Claude Opus 4.6
- Claude Opus 4.7
- Claude Opus 4.8
- Claude Opus 5
- Claude Opus 5.5
Sources
- Model deprecations - Claude Platform Docs (read 16 October 2026)
- Introducing Claude 2.1 (read 16 October 2026)
- Model Card and Evaluations for Claude Models; Claude 2.1 Model Card Appendix (read 16 October 2026)
- Model Pricing (read 16 October 2026)