GitHub Copilot Retires GPT-5.5, GPT-5.4, Gemini 3.7 Flash and Others on 19 October
GitHub will deprecate GPT-5.5, GPT-5.4, GPT-5.4 mini, GPT-5 mini, Gemini 3.7 Flash and Grok 4.5 across all Copilot experiences on 19 October 2026. The suggested replacements, what Business and Enterprise admins need to check, and what to update in workflows that name models.
GitHub announced that on 19 October 2026 it will deprecate several models across all GitHub Copilot experiences — Copilot Chat, inline edits, ask and agent modes, and code completions.
What's going and what replaces it
| Deprecated | Suggested replacement |
|---|---|
| GPT-5.5 | GPT-5.6 Sol |
| GPT-5.4 | GPT-5.6 Sol |
| GPT-5.4 mini | GPT-5.6 Luna |
| GPT-5 mini | GPT-5.6 Luna |
| Gemini 3.7 Flash | Gemini 3.8 Flash |
| Grok 4.5 | Grok 4.6 |
What you need to do
Individual users: if you've pinned one of these models in your editor or Copilot settings, pick the replacement before the 19th. Otherwise there's nothing to do.
Business and Enterprise admins:
- Under default model enablement, suggested alternatives are enabled automatically — unless an admin turned off the global default or disabled that model.
- If your organisation turned the global default off, enable the replacement models in your Copilot model policies, or users will lose those options.
- Deprecated models don't need manual removal.
Anyone with automation: update workflows, scripts and integrations that name a deprecated model explicitly.
Other Copilot news this month
- Claude Haiku 5.5 became available in Copilot on paid plans, billed at provider list prices under usage-based billing. (Claude Haiku 5.5 Released)
- Billing and policy changes for Business and Enterprise took effect around 1 October. (GitHub Copilot Billing Changes)
- GitHub Universe is on 28–29 October.
The general lesson
Every AI tool now rotates models every few months. Avoid hard-coding model names in long-lived automation where you can — use the tool's defaults or a single configuration value — and keep an eye on your providers' deprecation pages. (Claude Sonnet 4.5 Retirement)
Source: GitHub Changelog: Upcoming deprecation of selected Copilot models
EasySpawn works alongside whatever editor assistant you use: Claude Code runs on a persistent server with your own Claude plan, so model changes are yours to choose. See how it works or join the waitlist.
Related: What Is GitHub Copilot? · Claude Code vs GitHub Copilot · Cursor vs GitHub Copilot · Best AI Coding Tools
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