Anthropic Claude model family (as of 2026-09-30)
Anthropic builds the Claude family of large language models. Since mid-2026 the lineup has four generally available tiers (Fable, Opus, Sonnet, Haiku) plus an invite-only tier (Mythos).
Current lineup (generally available)
| Model | API ID | Released | Context / max output | Note |
|---|---|---|---|---|
| Claude Fable 5.1 | claude-fable-5-1 | 2026-09-01 | 1M / 128K | demanding reasoning, long-horizon agentic work |
| claude-opus-5 | claude-opus-5-5 | 2026-09-22 | 1M / 128K | long-running agentic coding and knowledge work; Anthropic’s suggested default |
| claude-sonnet-5 | claude-sonnet-5-5 | 2026-09-28 | 1M / 128K | best speed/intelligence mix |
| Claude Haiku 4.5 | claude-haiku-4-5-20251001 | 2025-10-15 | 200K / 64K | fastest, near-frontier; oldest model still listed as current |
Invite-only: Claude Mythos 5.1 (claude-mythos-5-1, 2026-09-01), same model as Fable 5.1, Project Glasswing participants only.
Tiers, as Anthropic positions them
- Fable: the top tier. A “Mythos-class” model released publicly with safety classifiers (cyber, bio/chem, distillation) that can decline requests. Slower, most expensive.
- Mythos: the same underlying model with those safeguards relaxed, for vetted defensive-cybersecurity (Project Glasswing) and life-science users. Not generally available.
- Opus: long-running agentic coding and knowledge work; middle of the price range. Anthropic says start here for most workloads and move to Fable when Opus at higher effort falls short.
- Sonnet: speed and intelligence balance, cheaper and faster than Opus.
- Haiku: fastest and cheapest.
How to choose
Start with Opus 5.5; use Sonnet 5.5 when latency/cost matter; Haiku 4.5 for high-volume, low-latency work (200K context, manual extended thinking, no effort parameter); Fable 5.1 when Opus 5.5 at higher effort still fails your evals. All current models take text and images and output text; current 5.x models use adaptive thinking, and non-default temperature/top_p/top_k are rejected from Opus 4.7 onward.
Legacy (still served) and retired
| Status | Models |
|---|---|
| Legacy, active | Fable 5 (not before 2027-06-09), claude-opus-5 (2027-07-24), claude-opus-4-dot-8 (2027-05-28), claude-opus-4-dot-7 (2027-04-16), Opus 4.6 (2027-02-05), Opus 4.5 (2026-11-24), claude-sonnet-5 (2027-06-30), Sonnet 4.6 (2027-02-17) |
| Deprecated | Sonnet 4.5 (deprecated 2026-09-30, retires 2026-11-30); claude-mythos-preview (deprecated 2026-06-09, retirement TBA) |
| Retired | Opus 4.1 (2026-08-05), Opus 4 and Sonnet 4 (2026-06-15), Haiku 3 (2026-04-20), Haiku 3.5 and Sonnet 3.7 (2026-02-19), Opus 3 (2026-01-05), Sonnet 3.5 (2025-10-28) |
Dates in parentheses are “not sooner than” retirement commitments on Anthropic-operated platforms (Claude API, Claude Platform on AWS, Microsoft Foundry); Bedrock and Google Cloud set their own. Anthropic gives at least 60 days’ notice before retiring a public model.
Deprecation calendar (next months)
| Date | Event |
|---|---|
| 2026-10-15 | Earliest possible retirement of Haiku 4.5 (no deprecation notice issued yet; with the 60-day notice policy, actual retirement cannot occur before roughly late Nov 2026 unless notice is given: inference) |
| 2026-11-24 | Earliest possible retirement of Opus 4.5 (no notice yet) |
| 2026-11-30 | Sonnet 4.5 retires (replacement: claude-sonnet-5-5) |
| 2027-02 onward | Opus 4.6 (02-05), Sonnet 4.6 (02-17) earliest retirement |
Claude products
Desktop app: Claude Desktop.
Claude models are served through the Claude API / Claude Platform, Amazon Bedrock, Google Cloud Vertex AI, Microsoft Foundry and Claude Platform on AWS; consumer/enterprise access via claude.ai and the Claude apps; and Claude Code for coding (Fable 5.1 announcement lists claude.ai, Claude Code and Enterprise).
Other Claude 4-era notes
Sources
- https://platform.claude.com/docs/en/about-claude/models/overview (accessed 2026-09-30)
- https://platform.claude.com/docs/en/about-claude/model-deprecations (accessed 2026-09-30)
- https://www.anthropic.com/news/claude-fable-5-mythos-5 (accessed 2026-09-30)
- https://www.anthropic.com/claude-fable-and-mythos-5-1 (accessed 2026-09-30)
- https://www.anthropic.com/glasswing (accessed 2026-09-30)