Gemini 3.5 Pro
Gemini 3.5 Pro is an unreleased flagship model from Google, announced at I/O in May 2026 but postponed after the base model was scrapped and rebuilt over disappointing coding performance. It was slated to feature a 2-million-token context window and Deep Think reasoning mode, but as of August 25, 2026, it remains in limited enterprise preview, with Google now training Gemini 4.