stealthmodels.

MODEL FIELD GUIDE

Gemini 3.8 Flash

A fast hosted model that accepts text, images, audio and video, with a million-token-class context.

A good fit for

High-volume media analysis and agents that need to work across documents, recordings and video through one API.

Context window
1,048,576tokens[1]
Model factsArchitecture, context & capabilities
First available
2026-09-02[2]
Developer
Google[1] [2]
Origin
United States[3]
Family
Gemini 3.8[1] [2]
Context window
1,048,576 tokens[1]
Maximum output
65,536 tokens[1]
Input
text, image, video, audio, PDF[1]
Output
text[1]
API access & pricingOpenRouter · $0.75 input / $3.75 output · per 1M tokens

Gemini Developer API; input 0.75 USD/1M; cached read 0.075/1M; output 3.75/1M; Introductory paid rate through 2026-12-31; published 2027 rates are higher. Free tier is also documented.

[5]
  • OpenRouterObserved 2026-10-06
    Input $0.75Output $3.75Cached read $0.075Cached write $0.04166667

    per 1M tokens

    google/gemini-3.8-flash[4]
  • Gemini Developer APIObserved 2026-10-06
    Input $0.75Output $3.75Cached read $0.075Batch input $0.375Batch output $1.875

    per 1M tokens

    Available

    gemini-3.8-flash[5]
Measurements & sources6 primary references · Speed & serving conditions

StealthMark score

StealthMark measures fluid and visual intelligence of AI models.

General and Visual

General Intelligence

Perspective, anatomy, correct shadows, purposeful detail and physical consistency.

Visual Intelligence

Likeness, anatomy, detail, light, materials, composition and artistic expression.

Judging

Frontier Models blindly judge the AI generation unbiased through an intricate process. Our researchers control for mistakes.

Overall score

Overall combines weighted task scores on a scale from 0 to 100. Repeating a task does not increase its weight. Estimated means the total includes an estimate for one missing scene.

Benchmaxxing

Benchmaxx flags models that score unusually well on the familiar Pelican task compared with their other benchmark results. The percentage measures that imbalance, not the probability of training contamination. Flagged Pelican scores are excluded from Overall. Pelican never counts toward General or Visual.

We keep some prompts private to discourage test-specific optimization.

Scoring categories

Prompt & likeness

Subjects, actions and likeness.

Anatomy & construction

Coherent bodies, joints and machinery.

Space & placement

Perspective, scale and contact.

Light & reflections

Lighting, shadows and reflections.

Purposeful detail

Clear, purposeful small features.

Artistry & character

Composition, expression and drawing skill.

Materials & effects

Surfaces, texture and movement.

Visual integrity

Clean shapes, layers and edges.

BENCHMARK RESULTS

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StealthMark benchmark results

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