Last verified: 8 September 2026. Official: Anthropic newsroom · system cards.
Direct Answer (8 September 2026): Public Claude runs from Claude 1 (March 2023) through Fable 5.1 (1 September 2026). Current generally available tiers: Fable 5.1, Opus 5, Sonnet 5, Haiku 4.5. Mythos 5.1 is not a public default. Living current-model box: current Claude model version.
2026 changelog (dated)
| Date | Release | Note |
|---|---|---|
| 1 Sept 2026 | Fable 5.1 / Mythos 5.1 | Newsroom: most capable public coding/knowledge-work model; Mythos restricted. |
| 24 July 2026 | Opus 5 | Current Opus. Max default. Same $5/$25 as Opus 4.8. |
| 1 July 2026 | Fable 5 / Mythos 5 restored | After mid-June access suspension. |
| 30 June 2026 | Sonnet 5 | Default on Free and Pro. $2/$10 API. |
| 9 June 2026 | Fable 5 / Mythos 5 | First public tier above Opus. Mid-June pause, then restore. |
| 28 May 2026 | Opus 4.8 | Opus upgrade; effort control on claude.ai. |
| 17 Feb 2026 | Sonnet 4.6 | Then production Sonnet; now superseded by Sonnet 5 as default. |
| Oct 2025 | Haiku 4.5 | Still the speed tier. |
Earlier generations (status)
Claude 1 → 2 → 3 / 3.5 / 3.7 → Claude 4 / 4.0 date-stamped IDs: historical. Original Sonnet 4 and Opus 4 (20250514) were the June 15, 2026 retirement class. Do not use them in new work.
The pattern that still holds: a new Sonnet often matches or beats the prior Opus at lower cost. Sonnet 5 vs Opus 4.8 is that move again.
FAQ
When was the latest Claude model released?
Fable 5.1 on 1 September 2026. Opus 5 on 24 July 2026. Sonnet 5 on 30 June 2026.
How many Claude versions are there?
More than a dozen public versions across five-plus generations. Four are current for most operators: Fable 5.1, Opus 5, Sonnet 5, Haiku 4.5.
Related: current models · pricing.
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