Model deprecations

As safer and more capable models launch, Anthropic regularly retires older ones. Applications relying on Anthropic models may need occasional updates to keep working. Impacted customers will always be notified by email and in the documentation.

This page lists all API deprecations, along with recommended replacements.

Overview

Anthropic uses the following terms to describe the model lifecycle:

• Active: The model is fully supported and recommended for use.
• Legacy: The model will no longer receive updates and may be deprecated in the future.
• Deprecated: The model is still functional but no longer recommended. Anthropic provides a recommended replacement and assigns a retirement date.
• Retired: The model is no longer available for use. Requests to retired models will fail.

Migrating to replacements

Once a model is deprecated, migrate all usage to a suitable replacement before the retirement date. Requests to models past the retirement date will fail.

To help measure the performance of replacement models on your tasks, consider thorough testing of your applications with the new models well before the retirement date.

For specific instructions on migrating to the latest Claude models, see the Migration guide.

Notifications

Anthropic notifies customers with active deployments for models with upcoming retirements, providing at least 60 days notice before model retirement for publicly released models.

Auditing model usage

To help identify usage of deprecated models, customers can access an audit of their API usage. Follow these steps:

1. Go to the Usage page in Claude Console
2. Click the "Export" button
3. Review the downloaded CSV to see usage broken down by API key and model

This audit will help you locate any instances where your application is still using deprecated models, allowing you to prioritize updates to newer models before the retirement date.

Best practices

1. Regularly check the documentation for updates on model deprecations.
2. Test your applications with newer models well before the retirement date of your current model.
3. Update your code to use the recommended replacement model as soon as possible.
4. Contact the support team if you need assistance with migration or have any questions.

Deprecation downsides and mitigations

Anthropic currently deprecates and retires models to ensure capacity for new model releases. This comes with downsides:

• Users who value specific models must migrate to new versions
• Researchers lose access to models for ongoing and comparative studies
• Model retirement introduces safety- and model welfare-related risks

At some point, Anthropic hopes to make past models publicly available again. In the meantime, Anthropic has committed to long-term preservation of model weights and other measures to help mitigate these impacts. For more details, see Commitments on Model Deprecation and Preservation.

Model status

Current and recently retired models are listed in the following table with their status:

Deprecation history

All deprecations are listed below, with the most recent announcements at the top.

2026-04-14: Claude Sonnet 4 and Claude Opus 4 models

On April 14, 2026, Anthropic notified developers using Claude Sonnet 4 and Claude Opus 4 models of their upcoming retirement on the Claude API.

2026-02-19: Claude Haiku 3 model

On February 19, 2026, Anthropic notified developers using Claude Haiku 3 model of its upcoming retirement on the Claude API.

2025-12-19: Claude Haiku 3.5 model

On December 19, 2025, Anthropic notified developers using Claude Haiku 3.5 model of its upcoming retirement on the Claude API.

2025-10-28: Claude Sonnet 3.7 model

On October 28, 2025, Anthropic notified developers using Claude Sonnet 3.7 model of its upcoming retirement on the Claude API.

2025-08-13: Claude Sonnet 3.5 models

On August 13, 2025, Anthropic notified developers using Claude Sonnet 3.5 models of their upcoming retirement.

2025-06-30: Claude Opus 3 model

On June 30, 2025, Anthropic notified developers using Claude Opus 3 model of its upcoming retirement.

2025-01-21: Claude 2, Claude 2.1, and Claude Sonnet 3 models

On January 21, 2025, Anthropic notified developers using Claude 2, Claude 2.1, and Claude Sonnet 3 models of their upcoming retirements.

2024-09-04: Claude 1 and Instant models

On September 4, 2024, Anthropic notified developers using Claude 1 and Instant models of their upcoming retirements.