Independent Claude history archive
The dated Claude model timeline, from Claude and Claude Instant on March 14, 2023 through Claude Fable 5.1 on September 1, 2026. Along the way: Sonnet 5 on June 30, 2026, Opus 5 on July 24, 2026, and text watermarking on August 14, 2026. Every entry carries an Anthropic-owned source. Drag the dates in The Scrubber. Verified September 19, 2026.
Signature experience
A film gate over the dated Claude line. Each frame is a frozen record of what was true that day: Fable 5.1 on 2026-09-01, Opus 5 on 2026-07-24, and the Sonnet 5 price permanence as a dated event that hands live rates to Claude Reports and Claude Central. Dates are not rewritten after the fact.
Fast citations
Latest archive snapshot
The latest entries belong here only when they alter the historical record, model status, pricing, prompt publication, or migration guidance.
Fable 5.1 launches as the most capable generally available Claude model at $10/$50 per MTok with cache reads cut to $0.25 per MTok. Mythos 5.1 shares the underlying model under trusted access only.
Source: Claude Fable 5.1 and Claude Mythos 5.1The $2/$10 per MTok rate announced as introductory through August 31, 2026 did not rise to $3/$15 on September 1. The pricing docs carry $2/$10 as the standard Sonnet 5 rate.
Source: PricingAnthropic announces that future Claude models watermark generated text for EU AI Act and Code of Practice transparency obligations. The watermark is global at launch, adds no tokens or hidden characters, and is not traceable to a person, organization, or conversation.
Source: Watermarking Claude text outputOpus 5 launches as the new Opus-class model at the same $5/$25 per MTok rate as Opus 4.8, becomes the default on Claude Max, and adds a fast mode at roughly 2.5x speed for 2x the base price.
Source: Claude Opus 5Sonnet 5 launches as the newest Sonnet model with introductory $2/$10 per MTok pricing announced as running through August 31, 2026.
Source: Introducing Claude Sonnet 5Archive rooms
Drag or step through every generally available Claude date through Fable 5.1. Each frame is frozen to that day.
Free toolsExplore the model timeline, compare historical API pricing, and check deprecated Claude model IDs in your browser.
Archive timelineA dated Claude model timeline from the March 2023 Claude launch through Claude Opus 5 and Claude Fable 5.1 in 2026.
Lifecycle archiveA source-cited ledger of deprecated and retired Claude model IDs, retirement dates, and official replacement guidance.
Price archiveA dated record of Claude API pricing events from Claude 2 through the September 1, 2026 Sonnet 5 price permanence and Fable 5.1 cache-read cut.
Prompt archiveA guide to Anthropic-published Claude system-prompt release notes, update dates, scope limits, and safe citation boundaries.
Migration archiveA source-cited migration map for moving from retired or older Claude model IDs to currently recommended replacements.
MethodologyThe primary-source bibliography and editorial method behind Claude Archive.
Boundary note
Claude Archive owns the dated timeline and nothing else. Which model to use right now is answered at Claude Central; pricing and benchmark analysis at Claude Reports; this week's news at Claude Weekly. This site records price events with a date on them and stays out of the current-rate business.