Service update · Google
Gemini 2.5 Pro and Flash deprecated; API redirects begin December 1
- Expected effective time
- Review updated
Google announced the deprecation of Gemini 2.5 Pro and 2.5 Flash on November 2; neither can now be selected in AI Studio. From December 1, 2026, API requests to gemini-2.5-pro will redirect to Gemini 3.8 Flash and requests to gemini-2.5-flash to Gemini 3.5 Flash-Lite, billed at the replacement model’s rates. Developers should update model strings and test migration beforehand. Breaking changes include function calling and thought_signature validation, thinking_level replacing thinking_budget, and removal of sampling parameters and prefilled model turns. Automatic routing does not guarantee a seamless migration.