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Model Passport / Google DeepMind / Gemini 3

Gemini 3.1 Pro Preview

Refines the Gemini 3 Pro series with better thinking, improved token efficiency, and more grounded, factually consistent output.

PreviewChecked Sep 1, 2026
01
Identity

What it is

Refines the Gemini 3 Pro series with better thinking, improved token efficiency, and more grounded, factually consistent output.

When to use it. Software engineering and multi-step automated workflows that need precise tool use.

Model DNA

9 identity dimensions, each read from a single field of this release's record and shown in the same order on every model. Nothing here is a score, a rating, or a ranking, and a dimension the record does not carry says so rather than being left out.

  • CreatorGoogle DeepMind
  • FamilyGemini 3
  • Generation3.1
  • TierPro
  • InputText, Image, Audio, Video
  • OutputText
  • SpecializationLanguage and reasoning, Multimodal generalist, Coding
  • AccessHosted API
  • WeightsNot recorded
What each segment means, and which field it comes from
Creator
Google DeepMindThe organization recorded as having built this release. A creator is not the same entity as a platform that serves the model or a product that ships it.Read from organizationId on this release record.How ModelTree keeps creator, model, product and platform separate
Family
Gemini 3The model line this release belongs to, as its creator names it. A family groups releases; it is not itself a release.Read from familyId on this release record.How ModelTree keeps creator, model, product and platform separate
Generation
3.1The version string the creator published for this release, recorded as written. ModelTree does not renumber, normalise, or order versions.Read from version on this release record.
Tier
ProThe variant name the creator gave this release within its family. It is a name, not a rank: what a creator means by it is recorded only where the creator has stated it.Read from variant on this release record.Why ModelTree publishes no universal ranking
Input
Text, Image, Audio, VideoThe kinds of input this release is documented as accepting.Read from inputModalities on this release record.
Output
TextThe kinds of output this release is documented as producing.Read from outputModalities on this release record.
Specialization
Language and reasoning, Multimodal generalist, CodingThe documented focus of this release. Categories are labels, never summed or weighted into a score.Read from categories on this release record.
Access
Hosted APIHow this release can be reached, as its creator documents it.Read from accessType on this release record.How ModelTree defines each access type
Weights
Not recordedWhether the licence record held for this release documents its weights as downloadable. Downloadable weights and an OSI-approved licence are separate claims, so this is not a statement that the release is open source.No licence record is held for this release. The schema requires one only where a release claims downloadable weights, so its absence is not a claim that the model is unlicensed.Read from license on this release record.What “open weight” means
Creator
Google DeepMind
Family
Gemini 3
Version
3.1
Variant
Pro
Released
Feb 19, 2026
Lifecycle status
Preview
Access
Hosted API
Record slug
gemini-3-1-pro-preview

Canonical record

Canonical name
Gemini 3.1 Pro Preview
Canonical page
/ModelTree/models/gemini-3-1-pro-preview/
Lifecycle
Preview. Announced and testable but not yet the vendor’s generally-available version. Recorded when the source calls it a preview, beta, or early access.

API identifiers

  • gemini-3.1-pro-preview
  • gemini-3.1-pro-preview-customtools
02
Lineage

Where it fits

Google DeepMindGemini 3Gemini 3.1 Pro Preview

What the tier names mean

Creator positioning is recorded for all 3 variant names in Gemini 3.

Tier names are recorded for one family and generation at a time, because the same word can mean different things in two generations of the same line. Entries are ordered by first release, which is not a ranking, and ModelTree draws no comparison between this family's names and any other creator's. How ModelTree treats guidance and ranking

ModelTree editorial noteGemini 3 carries three variant names across several releases, and a name here covers every release in this family that uses it. Google states the positioning for the series; ModelTree does not extend it to any other Gemini generation.Verified Aug 30, 2026

Pro tier — this release

Releases carrying this name: Gemini 3.1 Pro Preview

best for complex tasks that require broad world knowledge and advanced reasoning across modalities

ModelTree editorial summaryGoogle describes Pro here in terms of breadth — world knowledge, and reasoning that spans modalities. This is the Gemini 3 wording; Google words Gemini 2.5 Pro differently, which is why the two generations are recorded apart.Verified Aug 30, 2026

Flash-Lite tier

Releases carrying this name: Gemini 3.1 Flash-Lite, Gemini 3.5 Flash-Lite

a low-latency, cost-effective multimodal model optimized for high-frequency, lightweight tasks

ModelTree editorial summaryGoogle's Flash-Lite wording is about running a great deal of work rather than about how hard any single piece of it is. ModelTree reads that as a claim about throughput, not as a statement that Flash-Lite reasons less well than its siblings.Verified Aug 30, 2026

Flash tier

Releases carrying this name: Gemini 3.5 Flash, Gemini 3.6 Flash, Gemini 3.7 Flash

Gemini 3 Flash is our latest 3-series model, with Pro-level intelligence at the speed and pricing of Flash.

ModelTree editorial summaryGoogle defines Flash by reference to Pro inside the same series — a comparison drawn within one family rather than a rung on a ladder. ModelTree carries the wording as stated and adds no ordering of its own.Verified Aug 30, 2026

03
Technical record

Documented limits

Input modalities
text, image, audio, video
Output modalities
text
Context window
1,048,576 tokens
Maximum output
65,536 tokens
Parameters
Not recorded
Categories
  • Language and reasoning
  • Multimodal generalist
  • Coding
04
Access and licensing

How you can get it

Hosted API. Reachable only through a hosted API or product. No weights are distributed.

How ModelTree defines access and licensing

No licence record is held for this release. The schema requires one only where a release claims downloadable weights, so its absence here is not a claim that the model is unlicensed.

Coverage

What this passport does not record

These sections are absent from this page because no reviewed record exists for them. They are listed rather than dropped silently, because a missing section and a section ModelTree has decided nothing about look identical otherwise.

Where it is served
No deployment record ties this release to a serving platform. ModelTree has not yet reviewed platform availability for this record; absence is not a claim that the model is unavailable.
What it costs
No published price is recorded for this release. A price is held only against a reviewed deployment on a named platform, with its currency, unit, and effective date; absence is not a claim that the model is free or unpriced.
What has changed
No dated release event is recorded for this release beyond its release date. Announcement, availability, and deprecation events are held as separate sourced records, and none has been reviewed for this one.
05
Usage evidence

Who reports using it

No source-qualified usage evidence is recorded for Gemini 3.1 Pro Preview.

ModelTree records a usage figure only when a citable source states the metric, the population it measured, the time window, and the method behind it. Absence here means no qualifying observation has been verified, not that the model is unused.

How ModelTree qualifies usage evidence

Incompatible populations are never merged

Weekly users of one assistant, downloads from one model hub, and routed tokens on one aggregator count different populations. ModelTree groups observations only when the metric, the unit, and the measured population match exactly. Nothing is converted, normalized, weighted, or ranked, and there is no composite popularity score.

Sources are qualified, not scored

Every observation names the exact sources behind it and states whether it is a creator self-report, a platform operator report, an independent measurement, a developer survey, or a community signal. Creator self-reports are kept in their own labelled list because the creator has an interest in the figure; they are still shown, never hidden.

A synthesis needs two independent publishers

A cross-source statement may only be made when at least two non-creator observations from at least two different publishers measure the same metric over the same population. A single-source observation is still published as an observation, but it cannot produce a cross-source statement.

Missing and conflicting evidence stays visible

When no qualifying source exists, this section says so rather than estimating. When two qualifying sources disagree, both readings are shown and labelled as conflicting; neither is dropped and no winner is declared. A figure that has not been re-checked within 180 days is marked stale.

06
Conditional fit

When it fits, and when it does not

Everything in this section is ModelTree editorial synthesis: a reading of facts recorded elsewhere in this dataset, each traced to the sources beneath it. It is conditional guidance for a stated situation. It does not declare this model preferable to another, and no overall verdict is produced here or anywhere else in ModelTree.

No conditional-fit guidance is recorded for Gemini 3.1 Pro Preview.

A statement is published only when it can be derived from specific recorded facts about this release and cite the sources those facts already carry. Absence here means no such statement has been verified, not that the model suits every situation or none.

How ModelTree derives conditional fit

Guidance is conditional, never a verdict

Every statement is filed as one of three kinds — good fit when, trade-off, or avoid when — and each carries the condition it applies under. There is no fourth, unconditional kind, no composite score, and no comparison against other models.

What the wording check does, and what it cannot do

Validation refuses a fixed list of vocabulary in ModelTree’s own editorial text: superlatives, best-in-class and go-to framing, beats-everything phrasing, numeric rankings, universal quantifiers, and composite-score wording. That is a vocabulary filter, not a judgement about meaning. It catches the usual ways a verdict gets written down, but a comparative claim phrased around those words would pass it, and it errs toward rejecting borderline wording that an author can simply rephrase. The check that actually holds is provenance, below: a statement may cite only the sources the facts beneath it already cite, so a comparison cannot pull in a source no recorded fact carries. That constrains where evidence comes from, not what a sentence means. Neither check reads a statement and decides whether its facts support it — that judgement stays with you, which is why every statement lists the facts and sources it rests on.

The rubric is disclosed, not weighted

A statement names the dimensions it was derived from, and each dimension must be answered by a fact of a kind that can answer it. Dimensions are never added up or weighed against each other; they exist so a reader can see which questions were asked.

  • Context windowHow much input and output length does the documentation state?
  • Documented limitsWhat limits and intended uses does the documentation state outright?
  • Modality coverageWhich inputs and outputs are documented?
  • Access and licensingHow can it be obtained, and what does its licence permit?
  • Lifecycle stabilityWhat lifecycle stage do the vendor records place it in?
  • Cost structureWhat rates are recorded, in which unit and currency?
  • Measured benchmark evidenceWhat did a recorded evaluation measure, under which setup?
  • Usage evidenceWhat source-qualified usage has been observed, over which population?

The evidence threshold

A statement must rest on at least one structured fact already recorded here — a release or family field, a lifecycle event, an evaluation result, a usage observation, or a pricing record — and it must be a fact about this release. It may cite only sources those facts already cite, so guidance cannot pull in a source no recorded fact carries, and it cannot be dated earlier than the evidence beneath it.

Conflicts are shown, not resolved

When two statements about this release contradict each other on the same dimension, both are published and linked to one another. ModelTree does not decide between them, and the underlying disagreement between sources is left visible.

What this cannot tell you

Recorded facts are mostly documentation, and documentation states what an interface accepts rather than how well a model behaves. Where a dimension has no qualifying evidence, it is listed as a gap instead of being filled by inference. The date shown on a statement is the verification date of the newest fact beneath it, not a record that an editor re-read the reasoning; once that evidence is more than 180 days old the statement is marked stale. Nothing here is a recommendation tailored to a reader, and nothing here ranks models.

07
Provenance

Primary sources

Found something wrong on this page?Report incorrect data for gemini-3-1-pro-preview. Corrections are filed against the record slug so the fix lands on the right release.

Every fact above is recorded with the primary source it came from and the date it was last checked. This record was last verified on.How we verify and keep facts fresh.