Claude 1.0

Anthropic · March 2023

discontinuedCloseddecoder onlytextAPI Available
Parameters~52B
Context Window9K tokens
VariantsClaude, Claude Instant
Sunset DateMarch 2024

Why It Matters

First commercial model built with Constitutional AI, demonstrating that safety-focused training could produce a competitive assistant. Established Anthropic as a credible alternative to OpenAI.

Description

Anthropic's first publicly available AI assistant. Trained using Constitutional AI — a technique where the model learns safety guidelines from a set of written principles rather than relying solely on human feedback. Launched with a 9K token context window and a lighter 'Instant' variant.

Key Innovations

Constitutional AI
Constitutional AIAnthropic's approach to AI safety where the model critiques and revises its own outputs against a set of principles.
RLHF
RLHFReinforcement Learning from Human Feedback — training models to align with human preferences by having humans rank outputs.

Family Tree

Successors (1)

Related Research (2)

2017 · OpenAI / DeepMind

Pioneered the RLHF paradigm — training a reward model from human preferences, then using it to fine-tune policies via reinforcement learning.

2022 · Anthropic

Introduced RL from AI Feedback using "constitutions" (rule sets) for self-supervision, reducing reliance on human labels for harmlessness training.

External Links