claude-instant-1.0
Claude Instant 1.0 (Anthropic)
Yes — Claude Instant 1.0 is retired. Anthropic deprecated it on September 4, 2024 and shut it down on November 6, 2024; API requests to it now fail. The recommended replacement is Claude Haiku 4.5.
The first of Anthropic's cheap, fast models — the ancestor of everything now called Haiku. Instant traded depth for latency and price, which is what made Claude viable for classification and moderation work in 2023.
The facts
| Provider | Anthropic |
|---|---|
| Model id | claude-instant-1.0 |
| Released | — |
| Deprecated | September 4, 2024 |
| Shutdown | November 6, 2024 · 631 days ago |
| Status | Retired |
| Last verified | July 30, 2026 |
What to use instead
Two generations and a whole API separate these. Claude 1 predates the Messages API, so a migration means moving off /v1/complete and its "\n\nHuman:"/"\n\nAssistant:" prompt format entirely.
What parameters claude-haiku-4-5-20251001 accepts on modelparams.dev
Change the id
In most cases the migration is one string. Check the parameter differences before you ship — newer models drop older sampling knobs more often than they add them.
- "model": "claude-instant-1.0"
+ "model": "claude-haiku-4-5-20251001"
Frequently asked questions
- When did Anthropic Claude Instant 1.0 shut down?
- Anthropic Claude Instant 1.0 shut down on November 6, 2024. API requests to it fail from that date onward.
- What replaces Anthropic Claude Instant 1.0?
- Anthropic recommends Claude Haiku 4.5 (`claude-haiku-4-5-20251001`) as the replacement for Anthropic Claude Instant 1.0. Two generations and a whole API separate these. Claude 1 predates the Messages API, so a migration means moving off /v1/complete and its "\n\nHuman:"/"\n\nAssistant:" prompt format entirely.
- Is Anthropic Claude Instant 1.0 still available?
- No. Anthropic Claude Instant 1.0 is retired and no longer served — it was shut down on November 6, 2024. Calls to it return an error.
- How do I migrate from Anthropic Claude Instant 1.0 to claude-haiku-4-5-20251001?
- Swap the model id in your API call: replace "claude-instant-1.0" with "claude-haiku-4-5-20251001". Two generations and a whole API separate these. Claude 1 predates the Messages API, so a migration means moving off /v1/complete and its "\n\nHuman:"/"\n\nAssistant:" prompt format entirely.
Sources
- Anthropic model deprecations · platform.claude.com · accessed July 30, 2026
Found something wrong? The data is one YAML file — edit it on GitHub.
This page, for machines
Drop the badge in a README so it turns red the day this model is retired:
[](https://modeldeprecations.dev/anthropic/claude-instant-1.0)