# Anthropic Claude Sonnet 3 — deprecation status

> Yes — Claude Sonnet 3 is retired. Anthropic deprecated it on January 21, 2025 and shut it down on July 21, 2025; API requests to it now fail. The recommended replacement is Claude Sonnet 4.6.

The middle model of the original Claude 3 family, positioned between Haiku and Opus on the price ladder that every provider has copied since. Retired July 2025.

## Facts

| Field | Value |
| --- | --- |
| Provider | Anthropic |
| Model id | `claude-3-sonnet-20240229` |
| Status | Retired |
| Released | February 29, 2024 |
| Deprecated | January 21, 2025 |
| Shutdown | July 21, 2025 (374 days ago) |
| Last verified | July 30, 2026 |

## Replacement

- **Claude Sonnet 4.6** (`claude-sonnet-4-6`) · recommended — https://modeldeprecations.dev/anthropic/claude-sonnet-4-6
  - Two full generations separate these models. Prompts written to compensate for Sonnet 3's weaknesses usually hurt rather than help on 4.6.
  - Parameters it accepts: https://modelparams.dev/models/anthropic/claude-sonnet-4-6

```diff
- "model": "claude-3-sonnet-20240229"
+ "model": "claude-sonnet-4-6"
```

## FAQ

### When did Anthropic Claude Sonnet 3 shut down?

Anthropic Claude Sonnet 3 shut down on July 21, 2025. API requests to it fail from that date onward.

### What replaces Anthropic Claude Sonnet 3?

Anthropic recommends Claude Sonnet 4.6 (`claude-sonnet-4-6`) as the replacement for Anthropic Claude Sonnet 3. Two full generations separate these models. Prompts written to compensate for Sonnet 3's weaknesses usually hurt rather than help on 4.6.

### Is Anthropic Claude Sonnet 3 still available?

No. Anthropic Claude Sonnet 3 is retired and no longer served — it was shut down on July 21, 2025. Calls to it return an error.

### How do I migrate from Anthropic Claude Sonnet 3 to claude-sonnet-4-6?

Swap the model id in your API call: replace "claude-3-sonnet-20240229" with "claude-sonnet-4-6". Two full generations separate these models. Prompts written to compensate for Sonnet 3's weaknesses usually hurt rather than help on 4.6.

## Sources

- [Anthropic model deprecations](https://platform.claude.com/docs/en/about-claude/model-deprecations) — accessed 2026-07-30

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Canonical page: https://modeldeprecations.dev/anthropic/claude-3-sonnet-20240229
JSON: https://modeldeprecations.dev/api/v1/models/anthropic/claude-3-sonnet-20240229.json