WhichBot › What replaced it › What replaces Claude Sonnet 4.5?
Last checked Oct 28, 2026 · plain English · no paid picks
What replaces Claude Sonnet 4.5?
Short answer: Claude Sonnet 5.5. Anthropic announced the retirement on Sep 30, 2026, and Sonnet 4.5 switches off Nov 30, 2026.
What to do: Move to Claude Sonnet 5.5 before Nov 30, 2026.
The facts
| Old | Claude Sonnet 4.5 |
|---|---|
| Status | Retiring. Retirement announced Sep 30, 2026; retires Nov 30, 2026 |
| Replaced by | Claude Sonnet 5.5 |
| Official source | platform.claude.com |
| Last checked | Oct 28, 2026 |
The replacement at a glance
| Claude Sonnet 5.5 | |
|---|---|
| What it is | Anthropic's mid-size model |
| Made by | Anthropic |
| Price | Developer price: $2 in and $10 out per million tokens |
| Good at | Best for: writing, editing; Reads up to 1,000,000 tokens at once; Reads: text, image, PDFs |
| Where it runs | Claude Free+ |
| Status | Current. Not sooner than Sep 28, 2027 |
| Sources | platform.claude.com · claude.com · models.dev |
Related pages
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Questions people ask
What replaces Claude Sonnet 4.5?
Claude Sonnet 5.5. Anthropic announced the retirement on Sep 30, 2026, and Sonnet 4.5 switches off Nov 30, 2026.
What should I do if I used Claude Sonnet 4.5?
Move to Claude Sonnet 5.5 before Nov 30, 2026.
Facts come from the companies' own pages, linked above, and were last checked Oct 28, 2026. Prices are US and can change. Picks are Hector's: no paid picks, sponsors always labeled, and no sponsorship from AI labs. Our policy.