When will Gemini 3.5 Pro first become publicly available to ordinary users — selectable in the Gemini app (free or paid consumer tiers) AND callable via the Gemini API / Vertex AI / Google AI Studio on standard plans?

As of June 18, 2026, Gemini 3.5 Pro remains unreleased to the general public. Google announced the 3.5 series at Google I/O on May 19, 2026, shipping 3.5 Flash that day while stating 3.5 Pro was in internal testing and would be "rolling out next month" (June 2026) 44 sources. Currently, 3.5 Pro is limited to allowlisted Vertex enterprise preview and internal use, which does not satisfy the requirement for public availability 3 sources. It also remains absent from official release notes and API model documentation 44 sources.

The resolution criteria strictly demand public availability on both the consumer Gemini app and developer platforms (API/Vertex/AI Studio) on standard plans. While this sets a high bar, Google's precedent with previous flagship models, such as Gemini 3.1 Pro and Gemini 3 Pro, is a simultaneous release across consumer and developer surfaces on the same day blog.google.

A release before the end of June remains highly plausible given Google's firm public commitment and the classic end-of-quarter push. Market signals also reflect strong anticipation, implying roughly an 80% probability of a launch by June 30 polymarket.com. However, the median estimate is placed just past this deadline on July 1 to account for significant slip risk. The integration of ambitious features—such as a rumored 2M-token context window and the new, high-effort "Deep Think" mode aiweekly.co—introduces complex product-gating, pricing, and capacity challenges. Furthermore, any initial phased rollout, such as restricted trusted-tester access or an API-only drop prior to consumer availability, would delay resolution. Therefore, while late June is the likely target, a short slip into early-to-mid July is highly plausible, with the tail extending into August to cover potential scaling or safety hurdles.