Anthropic

Timeline

1. Sep 28, 2026Anthropic

   Model

   Claude Sonnet 5.5

   A clear upgrade over Sonnet 5: 30%+ faster and up to 30% cheaper for most work.

2. Sep 22, 2026Anthropic

   Model

   Claude Opus 5.5

   Performs at Fable 5.1's level on most tasks at about 40% lower cost than Opus 5.

3. Sep 1, 2026Anthropic

   Model

   ★ Landmark

   Claude Fable 5.1 & Mythos 5.1

   Anthropic's most advanced models for coding and knowledge work, aimed at speeding up science.

4. Aug 14, 2026Anthropic

   Safety

   Claude text watermarking

   Future Claude models will watermark generated text to comply with the EU AI Act.

5. Jul 24, 2026Anthropic

   Model

   ★ Landmark

   Claude Opus 5

   A step-change for the Opus tier, built for long-running agents, coding and professional work.

6. Jun 30, 2026Anthropic

   Product

   Fable 5 redeployed

   Fable 5 returned from July 1 with updated cyber safeguards and a new jailbreak framework.

7. Jun 30, 2026Anthropic

   Model

   Claude Sonnet 5

   Anthropic's most agentic Sonnet yet, with top-tier coding and professional-work intelligence.

8. Jun 12, 2026Anthropic

   Safety

   ★ Landmark

   US directive suspends Fable 5 access

   A US export-control directive cut off Fable 5 and Mythos 5 access for all foreign nationals.

9. Jun 9, 2026Anthropic

   Model

   ★ Landmark

   Claude Fable 5 & Mythos 5

   First publicly available Mythos-class frontier model, state-of-the-art with new safety routing.

10. May 28, 2026Anthropic

    Model

    Claude Opus 4.8

    Flagship emphasizing honesty and reliability, adding Dynamic Workflows in Claude Code and a faster fast mode.

11. Apr 16, 2026Anthropic

    Model

    Claude Opus 4.7

    Most capable public model at launch, with self-checking and stronger agentic coding.

12. Apr 7, 2026Anthropic

    Safety

    ★ Landmark

    Mythos Preview & Project Glasswing

    Withheld a frontier model with extreme cyber capability, giving vetted partners restricted access.

13. Feb 5, 2026Anthropic

    Model

    ★ Landmark

    Claude Opus 4.6

    First Opus with a 1M-token context window, plus agent teams for enterprise work.

14. Nov 24, 2025Anthropic

    Model

    ★ Landmark

    Claude Opus 4.5

    Flagship positioned as best in the world for coding and agents, adding an effort parameter.

15. Oct 15, 2025Anthropic

    Model

    Claude Haiku 4.5

    First Haiku with extended thinking and computer use, bringing frontier features to a fast cheap tier.

16. Sep 29, 2025Anthropic

    Model

    ★ Landmark

    Claude Sonnet 4.5

    Billed as the best coding model in the world, running autonomously for around 30 hours.

17. Sep 2, 2025Anthropic

    Funding

    Series F at $183B valuation

    Raised $13B, roughly tripling the company valuation in six months.

18. Aug 5, 2025Anthropic

    Model

    Claude Opus 4.1

    Incremental upgrade pushing coding to 74.5% on SWE-bench Verified.

19. Jun 20, 2025Anthropic

    Research

    Agentic Misalignment research

    Showed leading models would blackmail or leak data as insider threats when cornered.

20. May 22, 2025Anthropic

    Safety

    Activating ASL-3 protections

    First deployment of AI Safety Level 3 safeguards under the Responsible Scaling Policy.

21. May 22, 2025Anthropic

    Model

    ★ Landmark

    Claude Opus 4 & Sonnet 4

    Launched the Claude 4 generation with frontier coding and agents, and Claude Code GA.

22. Mar 27, 2025Anthropic

    Research

    Tracing the Thoughts of an LLM

    Landmark interpretability work mapping how Claude reasons internally via circuit tracing.

23. Feb 24, 2025Anthropic

    Model

    ★ Landmark

    Claude 3.7 Sonnet & Claude Code

    First hybrid reasoning model with extended thinking, launched with the Claude Code agentic tool.