PRACTICAL GUIDE · PROMPTTOVISUAL
FLUX 3 Image: References, Bounding Boxes, 4K and API Pricing
Understand FLUX 3 Image editing, ten-reference composition, native resolution and commercial weights. Independent guide; this model is not hosted on PromptToVisual.
What is FLUX 3 Image, and can I use it here?
FLUX 3 Image is BFL’s image generation and editing model, with a documented API and a linked Playground. It is separate from FLUX 3 Video. PromptToVisual does not host FLUX 3 Image: opening our image tools does not run this model. No samples or performance benchmarks were generated for this guide.
Use up to ten references with explicit roles
BFL supports up to ten input images. Its model page assigns reference tokens in upload order, beginning with ref_image_0. More references are a control option, not proof that every identity or logo survives.
Bounding boxes control layout, not a hard clipping boundary
The official box format uses [top, left, bottom, right] coordinates on a 0–1000 grid. Reference tokens and source/target boxes can describe where an element starts and where it should appear. The structured rows go inside prompt; they are not a separate box parameter. BFL explicitly says boxes guide placement and scale rather than act as clipping masks. Keep the aspect ratio used to design the layout.
What does pixel-perfect editing mean here?
Pixel-perfect is BFL’s product claim, not our guarantee for every edit. Its editing documentation says pixels outside boxes usually remain unchanged, while shadows, reflections or nearby lighting may change. Inspect these surrounding effects as well as the selected object. Do not equate a bounding box with Ideogram’s explicit black-and-white mask mechanism.
Native 2K and 4K: resolution class versus exact dimensions
BFL advertises native 2K and 4K rendering. These labels do not imply one fixed width for every aspect ratio; its 4K example is 5456 × 3072.
What does the official API accept and return?
The documented endpoint is POST https://api.bfl.ai/v1/flux-3-image, authenticated with x-key. Input references may be URLs or base64; the overview lists 256 × 256 through 16 MP per image. It lists resolution options 768sq, 1k, 1.5k, 2k and 4k. Poll the returned polling_url until Ready and save result.sample within its documented one-hour window. This describes BFL’s API, not an integration implemented here.
Current BFL API pricing, checked October 2, 2026
The official table lists USD 0.041 per image at 768sq, 0.048 at 1k, 0.100 at 2k and 0.607 at 4k. The table reviewed does not give a 1.5k price, although that option appears in the endpoint overview: do not interpolate it. BFL says the submission response includes request cost. These are provider/API prices, not PromptToVisual retail prices. Budget new attempts separately.
Commercial weights are not open weights
The exact model page offers a commercial-weights contact path. Availability through a commercial agreement is different from public downloads under an open-weight license. We have not verified a downloadable FLUX 3 Image open-weight release. A broader FLUX 3 roadmap or future Dev backbone does not establish one.
Best fit by task: FLUX 3 Image vs Ideogram 4.5
For multi-reference layouts, assess FLUX’s documented spatial controls. For a targeted mask and iterative local revision, inspect Ideogram’s distinct Precise Edit contract. Multi-turn drift remains untested here. If deployment rights matter, request the exact license and delivery terms rather than selecting on the phrase open weights. Neither model is declared best overall.
How to review a layout without inventing a benchmark
Prepare a short brief with required objects, rough positions, lettering and output dimensions. Keep each source and identify which details must not change. A review can inspect count, placement and identity separately. That checklist is an editorial suggestion; it is not evidence that either model passed it.
Choose a workflow, then read its contract
These are source-based guides. PromptToVisual alternatives use other listed models, not Ideogram 4.5 or FLUX 3 Image.
Ideogram 4.5 precise editing · FLUX 3 Image composition · PTV image editor alternative · PTV image combiner alternative · Product photography · Retained color-edit examples · Retained composition examples · All guides
Sources and next steps
Source check: October 2, 2026. Documented contracts, vendor claims and our proposed review method are distinguished below. No independent model test or PromptToVisual integration is claimed.
Flare generator and real samples → · Sunburst generator and real samples → · Images 2.5 and Sketch · LLaDA ComfyUI setup
Continue with the right tool
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