Black Forest LabsFLUX.1 Fill [pro]VSBlack Forest LabsFLUX.2 Klein 4B
Our Take
This matchup presents a clear distinction between specialized image editing and foundation generation. FLUX.1 Fill [pro] is a purpose-built model featuring dedicated specializations in Inpainting (Mask Fill) & Outpainting (Canvas Expansion) via a fast cloud API ($0.050/img). Meanwhile, FLUX.2 Klein 4B is engineered as a general foundation model. Choose FLUX.1 Fill [pro] if your workflow requires mask editing, fill tasks, or canvas expansion, or FLUX.2 Klein 4B for general image creation.
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Model Specs
FLUX.1 Fill [pro]
Pricing & Speed
Cost per Generation
$50.00per 1,000 imagesSpeed Tier
fastMax Resolution2K
Model Strengths
RealismHIGHPrompt AdherenceHIGHeditingHIGHoutput-qualityHIGHCharacter ConsistencyHIGHText RenderingHIGH
Model Specs
FLUX.2 Klein 4B
Open Source
Pricing & Speed
Cost per Generation3.6x cheaper
$14.00per 1,000 imagesSpeed TierFaster
real-timeMax Resolution4K
Model Strengths
RealismLOWPrompt AdherenceMEDIUMeditingLOWoutput-qualityLOWCharacter ConsistencyLOWText RenderingMEDIUM
Frequently Asked Questions about FLUX.1 Fill [pro] vs FLUX.2 Klein 4B
FLUX.2 Klein 4B is cheaper, costing $0.0140 per image generation compared to FLUX.1 Fill [pro] at $0.0500 per image.
FLUX.2 Klein 4B is faster, operating in the real-time speed tier compared to FLUX.1 Fill [pro] which is in the fast speed tier.
•FLUX.1 Fill [pro] is stronger in: Realism (High vs Low), Prompt Adherence (High vs Medium), Editing (High vs Low), Output Quality (High vs Low), Character Consistency (High vs Low), Text Rendering (High vs Medium).
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