No longer supported

This model is retired (released March 2023) and is no longer actively maintained or recommended by Anthropic. Consider using their current flagship model instead.

retiredlegacyllm Proprietary

Claude 1 (Legacy)

by Anthropic· Released March 2023· Cutoff December 2022

Claude 1 was Anthropic's first-generation large language model, focused on safety and helpfulness through constitutional AI. It was the predecessor to Claude 2 and later models, offering strong conversational abilities but with limited context and capabilities compared to modern versions.

Official Site API Docs 📄 Research Paper

Input cost

$2.90 per 1M tokens

Output cost

$8.60 per 1M tokens

Context window

9K tokens

Max output

4096 tokens

Modalities

text

License

proprietary

Capabilities

Text GenerationConversational AICode GenerationSummarizationQuestion Answering

Best For

Legacy applications requiring the original Claude 1 behavior; otherwise, use newer models.

Strengths

Strong safety alignment via constitutional AI
Good conversational coherence
Reasonable code generation for its time

Limitations

Very small context window (9K tokens)
No vision or multimodal support
No function calling or JSON mode
Outperformed by all subsequent Claude models
Retired and no longer recommended for new projects

Use Cases

Legacy system compatibility

Historical comparison studies

Simple text-based chatbots

Basic content summarization

Educational demonstrations of early LLMs

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