Flux Fill Pro
Black Forest Labs' mask-based inpainting model. Pixel-perfect localized edits — paint a mask over the region you want changed, describe what should fill it, the rest of the image is untouched. The complement to Flux Kontext: Kontext for instruction-based whole-image edits, Fill Pro for precision regional work.
At a glance
- Price
- 5 Credits
- Our rating
- Speed
- Average speed
What Flux Fill Pro is best for
How Flux Fill Pro performs
Strengths
- precision inpainting with mask control
- preserves untouched regions perfectly
- fast
Limitations
- requires mask input — not pure instruction-following
- less suited for text-only edit prompts
How to prompt Flux Fill Pro
Practical tips to get the most out of Flux Fill Pro.
- 01draw masks precisely — sloppy masks produce sloppy results
- 02describe what should fill the masked region
- 03use for localized edits, not full image transformations
Tips are tuned for Flux Fill Pro specifically.
Made with Flux Fill Pro
Prompt: a little red bird sitting on her head
Alternatives to Flux Fill Pro
Other models on Upsampler that cover similar ground.
Nano Banana 2 (with masking)
Google DeepMind's Gemini 3-powered flagship for text-to-image. Renders up to 4K with industry-leading prompt adherence, native multi-image references, and web search grounding for factual scenes. Ideal for product photography with brand consistency, character series across multi-shot campaigns, and complex compositional work that benefits from compositing several references at once.
Flux Kontext Pro
Black Forest Labs' instruction-based image editor — describe an edit in plain English ('replace the background with a sunset beach', 'change the shirt to red') and get a clean result that preserves the rest of the scene. Strong identity and lighting consistency makes it production-ready for outfit swaps, background replacement, and prop changes.
Frequently asked questions
What is Flux Fill Pro?
Black Forest Labs' mask-based inpainting model. Pixel-perfect localized edits — paint a mask over the region you want changed, describe what should fill it, the rest of the image is untouched. The complement to Flux Kontext: Kontext for instruction-based whole-image edits, Fill Pro for precision regional work.
How much does Flux Fill Pro cost on Upsampler?
5 credits per generation. No subscription, credits never expire.
What are alternatives to Flux Fill Pro?
Common alternatives: Nano Banana 2 (with masking), Flux Kontext Pro.
Can I try Flux Fill Pro for free?
You can try a free, no-signup version of our ai image editor. Note that the free version may use a different, lighter model rather than Flux Fill Pro itself.