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Anthropic ↗Released November 21, 2023

Claude 2.1

Undisclosed parameters

Claude 2.1 is Anthropic's entry in a crowded field. Context window: 0.2K tokens.

Context

200K

Input

$8.00

Key Specifications

🏆

Arena Rank

Not disclosed

📐

Context Window

200K

📥

Input Price

per 1M tokens

$8.00

📤

Output Price

per 1M tokens

$24.00

🧠

Parameters

Undisclosed

🔒

Open Source

No

Best For

Long documentsanalysisreduced hallucinations

About Claude 2.1

Claude 2.1, developed by Anthropic, is a large language model with a 200K token context window, one of the largest available at the time of its release. The model specializes in long-document analysis, summarization, and careful reasoning tasks. Its architecture incorporates Constitutional AI training methods to reduce hallucinations, with Anthropic reporting a 50% reduction in false statements compared to Claude 2.0. Claude 2.1 supports system prompts and tool use, enabling developers to build structured applications. Priced at $8.00 per million input tokens and $24.00 per million output tokens, it remains available through the Anthropic API. While now superseded by the Claude 3 family, Claude 2.1 was instrumental in establishing Anthropic's reputation for building safety-focused, high-capability language models suited for enterprise document workflows.

Built byAnthropic↗

Pricing per 1M tokens

Input Tokens

$8.00

Output Tokens

$24.00

Compare Claude 2.1

See how Claude 2.1 stacks up against other leading AI models

Claude 2.1 vs Claude Opus 4Compare →Claude 2.1 vs Claude Sonnet 4Compare →Claude 2.1 vs Claude 3 OpusCompare →Claude 2.1 vs Claude 3.5 SonnetCompare →Claude 2.1 vs Claude 3.5 HaikuCompare →

Other Anthropic Models

Claude Opus 4
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Claude Sonnet 4
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Claude 3 Opus
200K#7
Claude 3.5 Sonnet
200K#8
Claude 3.5 Haiku
200K#12

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Explore More

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Frequently Asked Questions

What is Claude 2.1?▾
Claude 2.1, developed by Anthropic, is a large language model with a 200K token context window, one of the largest available at the time of its release. The model specializes in long-document analysis, summarization, and careful reasoning tasks. Its architecture incorporates Constitutional AI training methods to reduce hallucinations, with Anthropic reporting a 50% reduction in false statements compared to Claude 2.0. Claude 2.1 supports system prompts and tool use, enabling developers to build structured applications. Priced at $8.00 per million input tokens and $24.00 per million output tokens, it remains available through the Anthropic API. While now superseded by the Claude 3 family, Claude 2.1 was instrumental in establishing Anthropic's reputation for building safety-focused, high-capability language models suited for enterprise document workflows.
How much does Claude 2.1 cost?▾
Input pricing for Claude 2.1 is $8.00 per million tokens; output runs $24.00. Token-based pricing means you can scale up or down without a fixed commitment.
What is Claude 2.1's context window?▾
The context window for Claude 2.1 is 200K tokens. That's the maximum amount of text you can feed into a single prompt, including system instructions, conversation history, and the actual query.
Is Claude 2.1 open source?▾
Claude 2.1 is closed-source and accessible only via Anthropic's API. Proprietary models trade deployment flexibility for convenience — Anthropic handles the infrastructure.
What is Claude 2.1 best for?▾
The sweet spot for Claude 2.1 is: Long documents, analysis, reduced hallucinations. If your workload fits one of these categories, it's worth benchmarking against alternatives.