GitHub Copilot Deprecates GPT-4.1 Model

What changed

GitHub Copilot has officially deprecated the GPT-4.1 model across all its integrated experiences. This deprecation took effect on June 1, 2026. The affected features include Copilot Chat, inline code editing, agent modes, and general code completion functionalities. The recommended alternative model for developers to transition to is GPT-5.5.

For GitHub Enterprise customers, administrators are advised to enable access to the GPT-5.5 model through their model policies within Copilot settings. Verifying the availability of the new model can be done by checking individual Copilot settings and ensuring the policy is active for GPT-5.5. Once enabled, the model will appear in the Copilot Chat model selector in environments like VS Code and on github.com. No explicit action is required to remove the deprecated GPT-4.1 model.

Why it matters for builders

This model deprecation necessitates an update to existing development workflows that rely on GitHub Copilot. Builders need to be aware of the transition from GPT-4.1 to GPT-5.5 to ensure continued access to AI-powered coding assistance. For those managing Copilot Enterprise instances, proactive configuration changes are required to maintain service continuity and leverage the updated model capabilities.

Practical impact

Developers should anticipate potential changes in the performance or behavior of their Copilot-assisted coding tasks. It is recommended to test the GPT-5.5 model in your development environment to understand its capabilities and any necessary adjustments to prompts or usage patterns. Administrators should review and update their Copilot model policies to include GPT-5.5 before the deprecation fully impacts their teams. For specific guidance or concerns, GitHub Enterprise customers are encouraged to contact their account manager.

Caveats and source limits

The provided source is a GitHub changelog announcement and does not include independent benchmarks or comparative performance data between GPT-4.1 and GPT-5.5. Specific details regarding the technical differences, performance improvements, or potential new features of GPT-5.5 are not elaborated upon. The exact date of full removal of GPT-4.1 is not specified beyond the deprecation notice.