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GitHub deprecated six selectable Copilot models — Gemini 3.7 Flash, GPT-5.5, GPT-5.4, GPT-5.4 mini, GPT-5 mini and Grok 4.5 — across most GitHub Copilot experiences on October 19, 2026, directing users to newer replacements.
left 19 Oct 2026
Quick answers
- Is it true that GitHub Copilot deprecated Gemini 3.7 Flash, GPT-5.5, GPT-5.4, GPT-5.4 mini, GPT-5 mini and Grok 4.5 on October 19, 2026?
- Yes — and the date has already passed (19 Oct 2026). On October 19, 2026, GitHub deprecated six models that had appeared in the GitHub Copilot model selector — **Gemini 3.7 Flash**, **GPT-5.5**, **GPT-5.4**, **GPT-5.4 mini**, **GPT-5 mini**, and **Grok 4.5** — across most Copilot experiences: Copilot Chat, inline edits, ask and agent modes, and code completions.
- When did it take effect?
- 19 Oct 2026 (already passed). Verified against the vendor's own announcement.
- What should I use instead?
- Move each deprecated model to its GitHub-suggested replacement: Gemini 3.7 Flash → **Gemini 3.8 Flash**; GPT-5.5 and GPT-5.4 → **GPT-6.1 Sol**; GPT-5.4 mini and GPT-5 mini → **GPT-6 Luna**; Grok 4.5 → **Grok 4.7**.
What this means for you
On October 19, 2026, GitHub deprecated six models that had appeared in the GitHub Copilot model selector — **Gemini 3.7 Flash**, **GPT-5.5**, **GPT-5.4**, **GPT-5.4 mini**, **GPT-5 mini**, and **Grok 4.5** — across most Copilot experiences: Copilot Chat, inline edits, ask and agent modes, and code completions. GitHub says the deprecation was announced ahead of time on September 18, 2026. For most individual developers this is a quiet change: no action is required to remove the models, and picking a model from the Copilot menu simply means choosing a supported one. The people who need to act are those who named one of these models by identifier — a script or integration that selects a Copilot model through the API, a CI step pinned to a specific model, or a Copilot Enterprise / Copilot Business policy that allow-lists particular models. After the deprecation those references no longer resolve to a live model, so a request that names a deprecated model fails or falls back rather than running on the intended one. Enterprise and Business administrators may have an extra step: the suggested replacements can require enabling through model policies in Copilot settings before users see them in the selector.
Where to go
Move each deprecated model to its GitHub-suggested replacement: Gemini 3.7 Flash → **Gemini 3.8 Flash**; GPT-5.5 and GPT-5.4 → **GPT-6.1 Sol**; GPT-5.4 mini and GPT-5 mini → **GPT-6 Luna**; Grok 4.5 → **Grok 4.7**. Update any workflow, integration, script, or configuration that names one of the retired models by identifier. Copilot Enterprise and Copilot Business administrators should enable the replacement models through their model policies in Copilot settings and confirm each appears in the Copilot Chat model selector in VS Code and on github.com, so users can actually pick it. Individuals who just choose a model from the Copilot menu need do nothing — the old option is gone and the replacement is available in its place. Enterprise customers with questions are directed to their GitHub account manager.
- Gemini 3.8 Flash — GitHub's suggested replacement for Gemini 3.7 Flash
- GPT-6.1 Sol — suggested replacement for GPT-5.5 and GPT-5.4
- GPT-6 Luna — suggested replacement for GPT-5.4 mini and GPT-5 mini
- Grok 4.7 — suggested replacement for Grok 4.5
GitHub deprecated six models from GitHub Copilot on October 19, 2026. In its changelog post, GitHub says the removal applies “across most GitHub Copilot experiences” — Copilot Chat, inline edits, ask and agent modes, and code completions — and that the deprecation was announced ahead of time on September 18, 2026.
The six models removed, with GitHub’s suggested replacements:
- Gemini 3.7 Flash → Gemini 3.8 Flash
- GPT-5.5 → GPT-6.1 Sol
- GPT-5.4 → GPT-6.1 Sol
- GPT-5.4 mini → GPT-6 Luna
- GPT-5 mini → GPT-6 Luna
- Grok 4.5 → Grok 4.7
Who this actually affects
For most people this is a quiet swap — the deprecated option simply disappears from the model picker in VS Code and on github.com and a supported model takes its place. GitHub says no action is required to remove the old models.
The sharper edge is for anyone who named one of these models by hand: a workflow, CI step, integration, or script that selects a Copilot model through the API, or an enterprise policy that allow-lists specific models. Those references stop resolving to a live model after the deprecation. GitHub adds that Copilot Enterprise administrators may need to enable access to the alternative models through their model policies in Copilot settings, then confirm each shows up in the Copilot Chat model selector before users can pick it.
What to do
Check anything that requests one of the six models by name and point it at the suggested replacement. Enterprise and Business admins should verify the replacements are enabled in their model policies. Individuals who choose a model from the Copilot menu need do nothing. Enterprise customers with questions are directed to their GitHub account manager.
This is the latest in GitHub’s rolling model-deprecation cadence for Copilot; see the related entries for the September and October 2026 rounds and the mid-November removals.
Entry changelog
- — last reviewed.
- — Entry created from GitHub's official changelog post (github.blog, 19 October 2026), which lists the six deprecated models, their 2026-10-19 deprecation date, and GitHub's suggested replacement for each. The post notes the deprecation was announced on 18 September 2026. Past-dated (status: passed) — the models were already removed when the entry was written. No detect: fingerprint — Copilot model choice is a service-side setting, not a dependency a repo scan can match reliably.
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