Flux Fill (mask) Image Editor
Mask-based inpainting and outpainting. Requires a region mask.
About Flux Fill (mask)
Flux Fill Pro is the only mask-based editor in this list — it requires you to provide both an image AND a mask defining the region to edit. This is the classic inpainting/outpainting workflow used by Photoshop's Generative Fill. Unlike instruction-based models, you get precise control over exactly which pixels change.
Heads up
Without a mask, this endpoint returns an error. It's not interchangeable with the other editors here.
Best use cases for Flux Fill (mask)
Where this model produces meaningfully better output than alternatives.
Precise inpainting
When you need to control exactly which region the AI touches and nothing else.
Outpainting (extending images)
Expand canvas beyond the original boundaries — fill in extended areas naturally.
Object removal with full control
Mask the object → describe the background → clean removal without artifacts elsewhere.
Style-transfer to a specific region
Apply a style change only to a masked region while preserving the rest.
Workflow integration with other tools
Most graphics editors export masks. Plug into existing Photoshop/Krita pipelines.
Tips for great results with Flux Fill (mask)
Practical tricks based on how this specific model was trained.
1. Make masks larger than you think you need
Why: Tight masks produce visible seams. Generous masks blend invisibly.
2. Describe what should be in the masked area, not what you want gone
Why: Fill models work by generating new content, not erasing — describe positively.
3. Use for surgical jobs, instruction models for casual
Why: Mask workflow is precise but slow. Reserve it for when you actually need that precision.
How Flux Fill (mask) compares
Quick comparison against the closest alternatives.
| Model | Maker | Tier | Best for |
|---|---|---|---|
| Flux Fill (mask) | Black Forest Labs | Standard | Precise inpainting |
| Flux Kontext Pro | Black Forest Labs | Recommended | Portrait edits without losing identity |
| Flux 2 Pro | Black Forest Labs | Standard | Multi-reference composition |
| SeedEdit | ByteDance | Standard | Surgical local edits |
Try Flux Fill (mask) on your own image
Upload any photo, describe what to change, and Flux Fill (mask) handles the rest.
Open editor →FAQ
What is Flux Fill (mask) and who made it?
Flux Fill (mask) was built by Black Forest Labs, released in 2025 (12B parameters). Flux Fill Pro is the only mask-based editor in this list — it requires you to provide both an image AND a mask defining the region to edit. This is the classic inpainting/outpainting workflow used by Photoshop's Generative Fill. Unlike instruction-based models, you get precise control over exactly which pixels change.
How does pricing work on renza?
Pay-as-you-go credits — no subscription, no monthly minimums. Credits never expire. New accounts get free credits to try things out. Each model has its own credit cost based on what it costs us to run; check the editor for current pricing on this model.
What kind of edits does Flux Fill (mask) handle well?
When you need to control exactly which region the AI touches and nothing else. Expand canvas beyond the original boundaries — fill in extended areas naturally. Mask the object → describe the background → clean removal without artifacts elsewhere. Limitation: Without a mask, this endpoint returns an error. It's not interchangeable with the other editors here.
How does Flux Fill (mask) compare to other editors?
Flux Fill (mask) is most often compared to Flux Kontext Pro, Flux 2 Pro, SeedEdit. The right pick depends on your specific use case — see "Best use cases" above for guidance, or open the editor and try them side by side on your own image.
Can I use the output commercially?
Yes. Generations made on renza are yours to use commercially. Standard FAL terms apply to the underlying models — none of the editors in this list restrict commercial use.
Is there a free trial?
Yes — new accounts get free credits at signup, enough to try a few different models. No credit card required.