Answer · Coding
What AI models does Claude Code use?
Claude Code runs on Claude 3.5 Sonnet (Anthropic), Fable 5 (Anthropic), Fable 5.1 (Anthropic), Haiku (Anthropic), Haiku 4.5 (Anthropic), Opus (Anthropic), Opus 5 (Anthropic), Sonnet (Anthropic), Sonnet 3.5 (Anthropic) and Sonnet 5 (Anthropic), and routes requests between them.
- Models used
- 10
- Primary model
- Fable 5
- Public API
- Yes
- Last checked
- 2026-09-12
Model claims are labelled by how we know them: Claude 3.5 Sonnet — inferred, Fable 5 — disclosed, Fable 5.1 — disclosed, Haiku — disclosed, Haiku 4.5 — disclosed, Opus — disclosed, Opus 5 — disclosed, Sonnet — disclosed, Sonnet 3.5 — inferred and Sonnet 5 — disclosed. "Disclosed" means the vendor says so in public; "inferred" means it was derived from documentation, headers or release notes.
Context window: 200k.
Other stack signals: cli, vscode-extension and desktop-app.
Cite this answer
Tomorrow. “What AI models does Claude Code use?” Tomorrow AI & Emerging Tech Index, AlienSquad, updated 2026-09-12. https://tomorrow.aliensquad.ai/q/what-models-does-claude-code-use
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