Migrating off claude-sonnet-4-6 — retirement date and replacement
Source last checked: 2026-11-02.
Anthropic is retiring claude-sonnet-4-6 on 2027-02-17 — in 104 days. The provider has not named a replacement in its own documentation, so the migration target is your decision. This page is built from Anthropic’s official deprecation notice and is rechecked weekly; the source link is below.
When is claude-sonnet-4-6 being deprecated?
| Model | Provider | Retires | Replacement |
|---|---|---|---|
| claude-sonnet-4-6 | Anthropic | 2027-02-17 | — not named |
Source: Anthropic deprecation notice
Test before switching
- Check the replacement's supported API endpoints and request parameters.
- Test your prompts, structured output, streaming and tool calls on staging.
- Compare quality, latency, pricing and rate limits on your workload.
- Keep a rollback path while the old model remains available.
Download retirement dates for your models.
What should I migrate claude-sonnet-4-6 to?
Anthropic has not published a successor for this model. Compare compatible alternatives using your workload, including output quality, latency, pricing and rate limits.
Measured latency of the Anthropic API host
| Region | p50 TTFB | p95 | Uptime | Probes |
|---|---|---|---|---|
| Asia (Tokyo) | 222 ms | 293 ms | 100% | 289 |
| Europe (Germany) | 180 ms | 210 ms | 100% | 289 |
| South America (São Paulo) | 195 ms | 242 ms | 100% | 289 |
| US (Central) | 91 ms | 160 ms | 100% | 289 |
Edge latency to the provider’s API host over the last 24 hours, measured from 4 regions. This measures the endpoint, not the model: swapping models on the same host is not an inference benchmark or a promise about the replacement model. Compare edge latency
Other Anthropic models being retired
| Model | Provider | Retires | Replacement |
|---|---|---|---|
| claude-sonnet-4-5-20250929 | Anthropic | 2026-11-30 | claude-sonnet-5-5 |
| claude-opus-4-1-20250805 | Anthropic | 2026-08-05 | claude-opus-4-8 |
| claude-sonnet-4-20250514 | Anthropic | 2026-06-15 | claude-sonnet-5-5 |
| claude-opus-4-20250514 | Anthropic | 2026-06-15 | claude-opus-4-8 |
| claude-3-haiku-20240307 | Anthropic | 2026-04-20 | claude-haiku-4-5-20251001 |
| claude-3-5-haiku-20241022 | Anthropic | 2026-02-19 | claude-haiku-4-5-20251001 |
| claude-3-7-sonnet-20250219 | Anthropic | 2026-02-19 | claude-sonnet-5-5 |
| claude-3-5-sonnet-20240620 | Anthropic | 2025-10-28 | claude-sonnet-5-5 |
How is this calendar maintained?
Entries are pulled from provider documentation by an automated weekly job and every one carries a link to its source. Nothing is inferred from blog posts or social media. When a provider changes a date, the change appears here after the next run and is visible in the changelog. The full calendar across all providers is on the deprecations page, and this provider’s own list is at Anthropic deprecations.