Gemini 3.1 Pro Is Gone From My Antigravity Model Selector. Here’s What I Can (and Can’t) Confirm

Description and use

Gemini 3.1 Pro vanished from Google Antigravity’s model selector, leaving only Gemini 3.8 Flash. The author confirms the disappearance via personal observation and a forum post, noting that Flash works well for scoped tasks but struggles with large rewrites.

Problem

The Gemini 3.1 Pro model disappeared from Google Antigravity’s model selector, leaving only Gemini 3.8 Flash as the available Gemini option.

Outcome

The author confirms that Gemini 3.1 Pro is no longer available in Antigravity, likely due to a rollout or planned deprecation, and notes that 3.8 Flash performs well on scoped tasks but struggles with large rewrites.

Workflow

• Open Antigravity model selector on Oct 13 2026
• Observe only Gemini 3.8 Flash listed
• Check Google AI Developers Forum for confirmation
• Review Antigravity models documentation and Gemini API deprecations page
• Compare performance of 3.8 Flash vs 3.1 Pro in personal tasks
• Document findings and recommend fallback strategies

Evidence

On October 13, 2026, I opened the model selector in Google Antigravity and found a single Gemini option: Gemini 3.8 Flash. Gemini 3.1 Pro, the model I used to treat as the safe, top-of-the-list choice, was not there.

Source

On the same day, another user posted on Google's developer forum that 3.1 Pro had quietly disappeared for Google AI Pro subscribers after a recent update, leaving 3.8 Flash as the only Gemini choice.

Source

Antigravity's models page carries a note that some models will be removed on November 2, 2026.

Source