Gemini 3.5 Pro
- Provider
- Status
- Preview
- Context
- 2,000,000 tok
Gemini 3.5 Pro is Google’s announced next flagship model, unveiled at Google I/O on 19 May 2026. Its headline features are a 2-million-token context window — the largest of any production frontier model, double the 1M on Gemini 3.5 Flash — and a built-in Deep Think reasoning mode for the hardest scientific, mathematical and coding problems (Tech Times).
It is still not generally available. As of 22 July 2026, Gemini 3.5 Pro remains in limited Vertex AI enterprise preview — its launch slipped past I/O, past a late-June target, and past a widely reported 17 July date that came and went. On 21 July 2026 Google shipped three new models — Gemini 3.6 Flash, Gemini 3.5 Flash-Lite and Gemini 3.5 Flash Cyber — but pointedly not 3.5 Pro (TechCrunch). Bloomberg reported that Google hit internal delays as the model struggled to meet its own performance goals, with Gemini 4 already in early training (9to5Google). Official benchmarks and pricing have never been published, so almost everything known about 3.5 Pro is announced specification or expectation rather than confirmed fact; this page flags which is which. Until it ships broadly, Gemini 3.1 Pro remains Google’s GA flagship, with the fast Gemini 3.5/3.6 Flash line the workhorse beneath it.
Quick specs
| Provider | |
| Announced | 19 May 2026 (Google I/O) |
| Status | Still not GA as of 22 July 2026 — limited preview; delayed past June and 17 July targets |
| Context window | 2,000,000 tokens (announced) |
| Reasoning | Built-in Deep Think mode |
| Pricing | Not published (reports expect ~$15/$60 — unconfirmed) |
| Benchmarks | Not published as of mid-June 2026 |
| Best for | Very long-context analysis, hardest reasoning, deep multimodal work |
| Limitations | Not generally available; specs largely announced/expected, not verified |
What is known (and not) about Gemini 3.5 Pro
Google positions Gemini 3.5 Pro to absorb the use cases previously routed to its Ultra tier: the hardest reasoning tasks, deep multimodal work and very long-context analysis (Enterprise DNA). Two things are officially announced:
- A 2M-token context window — double Gemini 3.5 Flash’s 1M and the largest in any production frontier model.
- A built-in Deep Think reasoning mode — extended chain-of-thought for hard science, maths and coding, building on the Gemini 3 Deep Think approach.
Beyond that, the picture is provisional. Official benchmarks and pricing have not been released. One report cited internal data suggesting 10–15-point SWE-bench Verified gains over the 3.1 generation, but that is unverified (Tech Times); and reports expect pricing around ten times Gemini 3.5 Flash — roughly $15 input / $60 output per million tokens — but Google has not confirmed it (byteiota). Treat both as expectations, not facts.
Availability and rollout
Gemini 3.5 Pro was announced at Google I/O on 19 May 2026, and its launch has slipped repeatedly. As of 22 July 2026 it remains in limited Vertex AI enterprise preview — it missed its late-June target and a widely reported 17 July date, and when Google shipped a batch of new models on 21 July 2026 (Gemini 3.6 Flash, 3.5 Flash-Lite and 3.5 Flash Cyber), 3.5 Pro was again absent (TechCrunch). Bloomberg reported the hold-up as an internal performance-goals problem, with Gemini 4 already in early training. Reports indicate 3.5 Pro will reach Google’s $20 AI Pro and $99.99 AI Ultra consumer plans first when it does land. Because it is not yet broadly available, our best AI models ranking lists it with “Limited” availability rather than as a model you can rely on today.
How Gemini 3.5 Pro is expected to compare
A clean, same-harness comparison is not yet possible because Google has not published benchmarks. Directionally, Gemini 3.5 Pro is expected to extend Google’s lead on context length (2M tokens) and multimodal breadth, and to challenge Claude Opus 4.8 and GPT-5.5 at the frontier — but until official numbers land, those are expectations. For verified, available models, see Gemini 3.1 Pro, Claude Opus 4.8 and GPT-5.5.
Known limitations
Not generally available. As of 22 July 2026 it is limited-preview only and has been delayed repeatedly (past June, past 17 July); most users cannot access it.
Specs are largely announced or expected. The 2M context and Deep Think mode are official; benchmarks and pricing are not, and circulating performance figures are unverified.
Expected high price. If the ~$15/$60 expectation holds, it would be among the more expensive frontier models — though again, unconfirmed.
FAQ
Is Gemini 3.5 Pro available yet?
No. It was announced at Google I/O on 19 May 2026 but, as of 22 July 2026, is still in limited Vertex AI enterprise preview — not generally available. It has slipped past its late-June target and a widely reported 17 July date, and Google’s 21 July model drop shipped new Flash models without it. Gemini 3.1 Pro remains Google’s current GA flagship.
When is the Gemini 3.5 Pro release date?
Google has not given a confirmed public release date. The model was announced on 19 May 2026 and has missed several rumoured targets (late June, then 17 July); as of 22 July 2026 it is still in limited enterprise preview, and Bloomberg reported internal delays over unmet performance goals. Treat any specific date circulating online as unconfirmed until Google announces one.
What is special about Gemini 3.5 Pro?
Two announced features stand out: a 2-million-token context window — the largest of any production frontier model — and a built-in Deep Think reasoning mode for the hardest problems.
How much will Gemini 3.5 Pro cost?
Google has not published pricing. Reports expect roughly ten times Gemini 3.5 Flash — about $15 input / $60 output per million tokens — but this is unconfirmed and should not be relied on.
How good is Gemini 3.5 Pro?
Unknown officially. Google has not released benchmarks; one unverified report suggested 10–15-point SWE-bench Verified gains over the 3.1 generation. We will add confirmed figures once Google publishes them.
Last verified 22 July 2026. Gemini 3.5 Pro is announced but not generally available, having slipped past its June and 17 July targets; its 2M context window and Deep Think mode are official, while benchmarks and pricing are unpublished and the figures cited here are reported expectations, not confirmed facts. Confirm against Google’s official pages once it ships.