---
id: "2023-03-14-claude-1"
url: "https://postcutoff.com/e/2023-03-14-claude-1/"
as_of: "2026-11-13T13:49:00+01:00"
date: "2023-03-14"
date_precision: day
category: model-release
importance: 4
confidence: high
status: [Confirmed]
sources: 2
editor: human editor
human_review: null
version: "2026-10-04"
---

As of: 2026-11-13 13:49 CET.
Researched and written by AI agents (Claude Opus 5.5 in Claude Code), with a human editor. How we work: https://postcutoff.com/about/
Canonical page: https://postcutoff.com/e/2023-03-14-claude-1/

# Anthropic releases Claude

Anthropic opened access to Claude, its AI assistant trained with Constitutional AI, in two versions: Claude and the faster, cheaper Claude Instant.

## Key facts
- Announced 14 March 2023 (same day as GPT-4)
- Two tiers: Claude and Claude Instant
- Available via chat interface and API to early partners (e.g. Notion, Quora's Poe, DuckDuckGo)
- Context window expanded to 100K tokens in May 2023

## What happened

Following closed testing, Anthropic made Claude available to businesses through an API and partner integrations.

## Why it matters

Started the Claude model family, which became a leading competitor to GPT models, especially in coding and agents.

## Your AI and this story

- GPT-6 Astra (training cutoff April 2026): in its training data
- Claude Opus 5.5 (training cutoff June 2026): in its training data
- Gemini 4 Hydrogen (training cutoff March 2026): in its training data
- Grok 4.7 (training cutoff May 2026): in its training data

## Sources

1. [Introducing Claude (Anthropic)](https://www.anthropic.com/news/introducing-claude) (anthropic.com, official)
2. [Introducing 100K Context Windows (Anthropic)](https://www.anthropic.com/news/100k-context-windows) (anthropic.com, official)

## Changes

- 2026-09-29 (filed): Created

## Related

- 2023-07-11: [Anthropic releases Claude 2 with public claude.ai access](https://postcutoff.com/e/2023-07-11-claude-2/index.md)
- 2022-12-15: [Anthropic introduces Constitutional AI (RLAIF)](https://postcutoff.com/e/2022-12-15-constitutional-ai/index.md)