Gemini 3.5 release date: what’s confirmed and what’s still rumor

Verdict: Gemini 3.5 does not have a confirmed release date. The strongest official evidence available here is Google’s Gemini API deprecations page, which lists Gemini 3.1 preview models but does not list a Gemini 3.5 model . That makes the current leak cycle worth watching, but not enough to treat Gemini 3.5 as an announced product.

What Google has actually documented

Google’s Gemini API deprecations page is the most useful official signal in the available evidence. It lists several Gemini 3 preview models, including gemini-3.1-pro-preview with a February 19, 2026 release date, gemini-3.1-flash-image-preview with a February 26, 2026 release date, and gemini-3.1-flash-lite-preview with a March 3, 2026 release date .

The same cited listing does not include a Gemini 3.5 entry . For release-date questions, that absence matters: screenshots, anonymous benchmarks, and social posts can suggest internal testing, but they do not establish public availability.

What the Gemini 3.5 leaks claim

The rumor cycle has two main threads.

First, several posts claim Google is testing a next-generation model called Gemini 3.5, sometimes under the alleged codename “Snow Bunny” . One report says the claim originated from an X post about an internal test version, and that the model could generate 3,000 lines of code from a single prompt . Another blog repeats similar “Snow Bunny” claims and describes them as leaked benchmark data rather than official Google results .

Second, some coverage points to alleged Google AI Studio A/B tests or hidden checkpoints. Geeky Gadgets describes leaked AI Studio testing under the working title “Gemini Advance,” with claimed gains in instruction-following and creative tasks but also inconsistencies in visual outputs and other areas . YouTube summaries are even less consistent: one says the alleged Gemini 3.5 test performed worse than Gemini 3.0 Pro, while another claims a 40% boost in coding and reasoning .

That inconsistency is the key issue. One YouTube snippet explicitly warns that anonymous benchmark screenshots and forum claims were not verified or reproducible . In other words, the leaks may be real signals of experimentation, but the available sources do not prove a released model, a stable benchmark, or a launch date.

Is there a likely Gemini 3.5 release window?

There is no evidence-backed date. Some rumor posts floated early-2026 timing, including February or March expectations . But the official Google listing cited here still shows Gemini 3.1 preview models and no Gemini 3.5 entry .

The only quantified timing signal in the available sources is a Manifold prediction market. It showed 34% odds for release before June 2026, 44% before July, 60% before August, and 67% before September . That points to a speculative mid-2026 expectation among bettors, not a Google roadmap.

The market’s own rules are a useful reality check: it counts a release only if the model is accessible without individual vetting or invitation, and it excludes closed betas, invite-only access, researcher programs, A/B tests, and anonymous benchmark appearances . By that standard, the current leak claims would not count as a public Gemini 3.5 launch.

How to know when Gemini 3.5 is actually confirmed

A credible public release should appear in an official Google channel, such as Gemini API documentation or a Google product announcement. In the available official documentation, Gemini 3.1 preview models are listed and Gemini 3.5 is not .

Until that changes, treat these as weak evidence rather than confirmation:

• anonymous benchmark screenshots;
• claimed internal codenames such as “Snow Bunny”;
• reports of hidden AI Studio checkpoints;
• A/B-test claims;
• YouTube videos repeating leak narratives;
• prediction-market timelines.

Those signals can be useful to monitor, but they are not the same as a release note, model card, API listing, or public product rollout.

Bottom line

Gemini 3.5 is not confirmed as a publicly released model, and there is no official release date in the available Google documentation . A summer 2026 window is a reasonable way to describe current speculation because prediction-market expectations cluster around June through August, but it should be labeled speculation unless Google publishes an official Gemini 3.5 listing or announcement .