Category: Anthropic models

This category contains 18 pages.

  • Claude (model family) · Anthropic's assistant model line, from Claude 1 (2023) through the Claude 4.x series to the Fable/Mythos 5 generation (2026).
  • Claude 1 · Anthropic's first publicly released chat assistant (March 2023), notable for its Constitutional AI alignment approach and later 100K-token context window.
  • Claude 2 · Anthropic's July 2023 model; its 100K-token context window was the era's longest, and its cautious refusals defined early Claude's reputation.
  • Claude 3 · Anthropic's March 2024 generation (Haiku, Sonnet, Opus); Opus was the first model to consistently challenge GPT-4-class results.
  • Claude 3.5 Haiku · Anthropic's fast, low-cost model of the Claude 3.5 generation, announced in October 2024 as the successor to Claude 3 Haiku.
  • Claude 3.5 Sonnet · Anthropic's mid-2024 workhorse; beat Claude 3 Opus at twice the speed, and its October refresh introduced computer use.
  • Claude 3.7 Sonnet · Anthropic's February 2025 hybrid reasoning model: one network serving instant and extended-thinking modes, launched alongside Claude Code.
  • Claude 4 · Anthropic's May 2025 generation (Opus 4, Sonnet 4), built for agentic coding; Opus 4 was the first model deployed under ASL-3 safeguards.
  • Claude Fable 5 · Anthropic's June 2026 frontier model, first of the Mythos-class tier above Opus; briefly suspended under a US export-control directive.
  • Claude Haiku 4.5 · Anthropic's October 2025 small model, the first Haiku with extended thinking, offering developer-reported near-Sonnet-4 coding performance at a fraction of the cost.
  • Claude Instant · Anthropic's lighter, faster, lower-cost assistant line launched alongside the original Claude in March 2023 and retired after the Claude 3 generation introduced Haiku.
  • Claude Opus 4.1 · Anthropic's August 2025 incremental upgrade to Claude Opus 4, with developer-reported gains in agentic coding and long-horizon reasoning.
  • Claude Opus 4.5 · Anthropic's November 2025 flagship: developer-reported coding leadership with a major price cut, closing the Claude 4.x series.
  • Claude Opus 4.6 · Anthropic's February 2026 flagship, adding a beta 1M-token context window, adaptive thinking, and effort controls to the Opus line.
  • Claude Opus 4.8 · Anthropic's May 2026 Opus flagship, adding dynamic workflows, a discounted fast mode, and developer-reported gains in coding honesty; the last Opus release before Claude Fable 5.
  • Claude Opus 5 · Anthropic's July 2026 Opus release, positioned as approaching Claude Fable 5's capability at half its price; the first Opus-tier model of the Claude 5 generation.
  • Claude Sonnet 4.5 · Anthropic's September 2025 mid-tier hybrid reasoning model, marketed at launch as the company's strongest model for coding and computer use.
  • Claude Sonnet 5 · Anthropic's June 2026 mid-tier model, marketed as its most agentic Sonnet, released as the default model for Free and Pro plans.