Model Comparison

Flux 2 Dev vs Gemini 3 Pro Image

Black Forest Labs' open-weight flagship meets Google's most powerful image model. This comparison explores when the 11x cost difference delivers proportional value—and when Flux 2 Dev's quality is simply good enough.

Comparison10 min read
Background

Open-Weight Excellence vs Flagship Multimodal

Flux 2 Dev represents the pinnacle of open-weight image generation. Created by Black Forest Labs—a team with roots in the original Stable Diffusion project—it sits at the top of the FLUX.2 family, offering full quality without the proprietary restrictions of Pro. With roughly 2.5-second generation times and very low cost per image, it delivers remarkable value for high-quality image synthesis.

Gemini 3 Pro Image is Google's flagship image generation system, representing their most advanced multimodal capabilities. Unlike dedicated diffusion models, Gemini 3 Pro operates as part of a massive language model that understands images at a fundamental level. With an ELO rating of approximately 1235—nearly 100 points above Flux 2 Dev—it consistently ranks among the very best models in blind preference testing.

The ELO gap of ~92 points is substantial. In arena testing, this translates to Gemini 3 Pro winning roughly 63% of head-to-head comparisons. But raw quality differences tell only part of the story. Gemini 3 Pro excels at understanding nuanced prompts, rendering accurate text, and composing complex scenes with proper spatial relationships. These capabilities come from its foundation as a language model that genuinely understands what it's creating.

The practical question isn't whether Gemini 3 Pro is better—the benchmarks confirm that it generally is. The question is whether your specific use case benefits from that quality gap enough to justify an 11x cost increase and 3x longer generation time. For many applications, Flux 2 Dev produces images that are more than sufficient. For others, only the best will do.

Tip: Consider your volume and quality requirements carefully. A single premium hero image may justify Gemini 3 Pro's cost, while a batch of 20 product variants might be better served by Flux 2 Dev—the 11x cost savings allows for many more iterations within the same budget.

Side by Side

Visual Comparison

Compare outputs from both models using identical prompts. Pay attention to fine details, text accuracy, and how each model interprets complex concepts.

PromptFlux 2 DevGemini 3 Pro Image
Fine Art DetailRenaissance portrait of a noblewoman, soft sfumato technique, subtle smile reminiscent of da Vinci, rich velvet dress with intricate embroidery, golden light from a nearby window
Flux 2 Dev - Fine Art Detail
Model: flux-2-dev
Renaissance portrait of a noblewoman, soft sfumato technique, subtle smile reminiscent of da Vinci, rich velvet dress with intricate embroidery, golden light from a nearby window
Gemini 3 Pro Image - Fine Art Detail
Model: gemini-3-pro-image-preview
Renaissance portrait of a noblewoman, soft sfumato technique, subtle smile reminiscent of da Vinci, rich velvet dress with intricate embroidery, golden light from a nearby window
Complex SceneA bustling Tokyo intersection at night during rainfall, neon reflections on wet pavement, hundreds of umbrellas creating a sea of color, motion blur on passing vehicles
Flux 2 Dev - Complex Scene
Model: flux-2-dev
A bustling Tokyo intersection at night during rainfall, neon reflections on wet pavement, hundreds of umbrellas creating a sea of color, motion blur on passing vehicles
Gemini 3 Pro Image - Complex Scene
Model: gemini-3-pro-image-preview
A bustling Tokyo intersection at night during rainfall, neon reflections on wet pavement, hundreds of umbrellas creating a sea of color, motion blur on passing vehicles
Technical PrecisionProfessional watch photography: a luxury dive watch showing exactly 10:10 on the dial, water droplets on the crystal, brushed titanium case, underwater caustic light patterns
Flux 2 Dev - Technical Precision
Model: flux-2-dev
Professional watch photography: a luxury dive watch showing exactly 10:10 on the dial, water droplets on the crystal, brushed titanium case, underwater caustic light patterns
Gemini 3 Pro Image - Technical Precision
Model: gemini-3-pro-image-preview
Professional watch photography: a luxury dive watch showing exactly 10:10 on the dial, water droplets on the crystal, brushed titanium case, underwater caustic light patterns
Abstract ConceptThe feeling of nostalgia personified: an elderly figure made of fading photographs standing in a sunlit room, dust motes floating, warm sepia tones bleeding into color
Flux 2 Dev - Abstract Concept
Model: flux-2-dev
The feeling of nostalgia personified: an elderly figure made of fading photographs standing in a sunlit room, dust motes floating, warm sepia tones bleeding into color
Gemini 3 Pro Image - Abstract Concept
Model: gemini-3-pro-image-preview
The feeling of nostalgia personified: an elderly figure made of fading photographs standing in a sunlit room, dust motes floating, warm sepia tones bleeding into color
Natural WorldA red fox in a snow-covered forest at dawn, breath visible in cold air, morning light filtering through frosted pine branches, pristine powder snow undisturbed
Flux 2 Dev - Natural World
Model: flux-2-dev
A red fox in a snow-covered forest at dawn, breath visible in cold air, morning light filtering through frosted pine branches, pristine powder snow undisturbed
Gemini 3 Pro Image - Natural World
Model: gemini-3-pro-image-preview
A red fox in a snow-covered forest at dawn, breath visible in cold air, morning light filtering through frosted pine branches, pristine powder snow undisturbed

New to ImageGPT?

ImageGPT provides access to both Flux 2 Dev and Gemini 3 Pro Image through a single API. Use Flux 2 Dev for cost-effective quality production, then switch to Gemini 3 Pro when maximum quality matters—no provider management required. Start with a 7-day free trial.

Recommendations

When to Use Each Model

Choose based on quality requirements, budget, and whether your prompts require deep semantic understanding.

Flux 2 Dev

  • High-volume generation where consistency matters
  • Projects with budget constraints (11x cost savings)
  • Rapid iteration and exploration phases
  • Workflows requiring fast turnaround (~2.5s vs ~8s)
  • Use cases where open-weight flexibility is valuable

Gemini 3 Pro Image

  • Hero images and premium marketing assets
  • Complex scenes with multiple interacting elements
  • Prompts requiring accurate text rendering
  • Abstract or conceptual images needing interpretation
  • Final deliverables where maximum quality is non-negotiable
Deep Dive

The Premium Quality Gap

Examining where Gemini 3 Pro's flagship status is most visible.

Flux 2 Dev
"A photorealistic portrait of an elderly Japanese fisherman, ..."
Flux 2 Dev result
Model: flux-2-dev
A photorealistic portrait of an elderly Japanese fisherman, weathered face telling stories of decades at sea, early morning harbor light, traditional indigo work clothes, rope textures and fishing nets in background
Gemini 3 Pro Image
"A photorealistic portrait of an elderly Japanese fisherman, ..."
Gemini 3 Pro Image result
Model: gemini-3-pro-image-preview
A photorealistic portrait of an elderly Japanese fisherman, weathered face telling stories of decades at sea, early morning harbor light, traditional indigo work clothes, rope textures and fishing nets in background

Portrait photography of faces with character presents one of the most demanding tests for image generation. The subtle variations in skin texture, the way light interacts with weathered features, the storytelling quality of an expressive face—these elements separate good images from exceptional ones.

In our testing, Gemini 3 Pro tended to produce more nuanced skin rendering, with subtler color variations and more believable texture. The lighting often felt more natural, with softer transitions between highlights and shadows. Flux 2 Dev produced strong results, but occasionally with slightly more uniform skin tones or less naturalistic light falloff. For hero portraits where every detail matters, this difference can be significant.

Note: Human faces are where multimodal models often excel—their deep understanding of facial structure and expression, learned from analyzing millions of images with captions, produces more nuanced results than pattern-matching alone.

Deep Dive

Complex Scene Composition

Testing how each model handles prompts with multiple interacting elements.

Flux 2 Dev
"A busy farmer's market at sunrise, elderly vendor arranging ..."
Flux 2 Dev result
Model: flux-2-dev
A busy farmer's market at sunrise, elderly vendor arranging colorful produce, young mother with child selecting tomatoes, chef in whites examining herbs, morning mist rising between stalls, golden hour light streaming through gaps
Gemini 3 Pro Image
"A busy farmer's market at sunrise, elderly vendor arranging ..."
Gemini 3 Pro Image result
Model: gemini-3-pro-image-preview
A busy farmer's market at sunrise, elderly vendor arranging colorful produce, young mother with child selecting tomatoes, chef in whites examining herbs, morning mist rising between stalls, golden hour light streaming through gaps

This prompt describes multiple distinct characters, each with specific actions and attributes, within a coherent environment. Getting the spatial relationships right—who is where, how they interact with their surroundings, how the light affects everything—requires understanding the scene as a unified whole rather than assembling individual elements.

Gemini 3 Pro's language model foundation gives it an advantage here. It can parse the prompt's structure, understand the relationships between elements, and compose a scene where everything makes spatial and logical sense. Flux 2 Dev sometimes produced images where the composition felt more random—beautiful individual elements that didn't quite cohere into a unified scene as reliably.

Tip: When your prompt describes multiple characters or complex interactions, Gemini 3 Pro's semantic understanding often produces more coherent compositions on the first attempt.

Deep Dive

Text Rendering Accuracy

Comparing how accurately each model handles text within images.

Flux 2 Dev
"Vintage movie poster for 'THE LAST HORIZON', 1950s aesthetic..."
Flux 2 Dev result
Model: flux-2-dev
Vintage movie poster for 'THE LAST HORIZON', 1950s aesthetic, a silhouetted figure standing on a cliff overlooking a vast canyon at sunset, bold typography, credits reading 'Starring James Dean and Audrey Hepburn'
Gemini 3 Pro Image
"Vintage movie poster for 'THE LAST HORIZON', 1950s aesthetic..."
Gemini 3 Pro Image result
Model: gemini-3-pro-image-preview
Vintage movie poster for 'THE LAST HORIZON', 1950s aesthetic, a silhouetted figure standing on a cliff overlooking a vast canyon at sunset, bold typography, credits reading 'Starring James Dean and Audrey Hepburn'

This prompt includes multiple distinct text elements: a movie title, specific cast names, and the overall typography style of vintage Hollywood. Text rendering has historically been a weakness of image generation models, but multimodal systems have made significant progress.

Gemini 3 Pro demonstrated notably more reliable text rendering in our testing. The title "THE LAST HORIZON" was more consistently legible, and the cast names—even complex ones like "Audrey Hepburn"—appeared correctly more often. Flux 2 Dev sometimes garbled longer text or substituted similar-looking characters. For any image where text legibility is important, this capability difference is substantial.

Deep Dive

Abstract Concept Interpretation

How each model visualizes ideas rather than concrete scenes.

Flux 2 Dev
"The moment before a breakthrough: a scientist's desk covered..."
Flux 2 Dev result
Model: flux-2-dev
The moment before a breakthrough: a scientist's desk covered with equations and diagrams, one piece of paper with the answer just becoming visible, golden light beginning to illuminate the solution, tension between chaos and clarity
Gemini 3 Pro Image
"The moment before a breakthrough: a scientist's desk covered..."
Gemini 3 Pro Image result
Model: gemini-3-pro-image-preview
The moment before a breakthrough: a scientist's desk covered with equations and diagrams, one piece of paper with the answer just becoming visible, golden light beginning to illuminate the solution, tension between chaos and clarity

This prompt describes a feeling, a moment, a concept—not a concrete scene. The "moment before a breakthrough" is abstract; the image needs to capture anticipation, the transition from confusion to clarity. This requires interpreting intent, not just rendering described objects.

Gemini 3 Pro's multimodal understanding showed clearer advantages with conceptual prompts like this. Images more often captured the intended emotional arc, with composition and lighting that supported the narrative. Flux 2 Dev produced technically competent images of desks with papers, but the abstract quality—the "moment before"—was less consistently present in the final image.

Note: When prompting for emotions, concepts, or abstract ideas rather than concrete scenes, Gemini 3 Pro's language understanding translates to more intentional interpretations.

Deep Dive

Economic Analysis

When does the quality premium justify the 11x cost?

Flux 2 Dev (~2.5s)
"Professional food photography: artisan sourdough bread on ru..."
Flux 2 Dev (~2.5s) result
Model: flux-2-dev
Professional food photography: artisan sourdough bread on rustic wooden board, steam rising from fresh slice, scattered flour and wheat stalks, warm bakery lighting, shallow depth of field
Gemini 3 Pro (~8s, 11x cost)
"Professional food photography: artisan sourdough bread on ru..."
Gemini 3 Pro (~8s, 11x cost) result
Model: gemini-3-pro-image-preview
Professional food photography: artisan sourdough bread on rustic wooden board, steam rising from fresh slice, scattered flour and wheat stalks, warm bakery lighting, shallow depth of field

For this straightforward food photography prompt—a clear subject, well-established visual conventions—both models produce excellent results. This is the scenario where Flux 2 Dev's value proposition is strongest: professional-quality output at a fraction of the cost.

With Gemini 3 Pro costing roughly 11x more per image, you can generate 11 variations with Flux 2 Dev for the cost of one Gemini 3 Pro image. For exploration, iteration, and production of content where the prompt is concrete and the subject is well-defined, this economic advantage is decisive. Reserve Gemini 3 Pro for prompts where its superior understanding and quality genuinely improve the outcome—complex compositions, abstract concepts, text-heavy images, or final hero deliverables.

Tip: A practical workflow: explore and iterate with Flux 2 Dev to find your ideal composition, then generate the final version with Gemini 3 Pro if maximum quality is required for that specific image.

Specifications

Feature Comparison

Technical specifications and capabilities for both models.

FeatureFlux 2 DevGemini 3 Pro Image
Release20252025
ArchitectureFLUX.2 DiffusionMultimodal LLM
CreatorBlack Forest LabsGoogle
Image qualityVery GoodExcellent
Text renderingModerateStrong
Semantic understandingGoodExcellent
Generation speed~2.5s~8s
Cost per image (1MP)$$$$$$$$$$$$
Image input support
Aspect ratio options9 ratios10 ratios
Prompt adherenceVery GoodExcellent
ELO rating~1143~1235
Open weights
Try It Yourself

Try Flux 2 Dev

Generate your own images and experience the quality difference firsthand. Try complex prompts with text elements to see where Gemini 3 Pro's understanding shines.

Generated visual
https://demo.imagegpt.host/image?prompt=A+master+calligrapher%27s+hands+creating+an+intricate+illuminated+manuscript%2C+gold+leaf+catching+candlelight%2C+ink-stained+fingers+guiding+a+quill+with+precision%2C+ancient+wooden+desk+covered+with+pigments+and+brushes&model=flux-2-dev

Frequently Asked Questions

Premium or practical.
Match the model to the moment.