FLUX 3 Image boxes versus FLUX.2 prompt edits
Use FLUX 3 Image when the layout itself is the spec: ids, a 0–1000 box, and a description per element. Use FLUX.2 [pro] when a written edit is enough and you want the lower published starting price.
Both products are from Black Forest Labs and both are on api.bfl.ai. They are not interchangeable request bodies. Figures below are from the pricing page fetched 3 October 2026. No quality scores are compared here, because neither page publishes one.
| FLUX 3 Image | FLUX.2 [pro] | |
|---|---|---|
| What you send for placement | JSON rows inside prompt. Generation uses id, bbox, desc. Edits use from, src_bbox, tgt_bbox. See the box guide. | A text prompt plus optional input images on /flux-2-pro. The FLUX 3 box schema is not that endpoint. |
| References | 1 to 10, named ref_image_0 onward, 256×256 to 16 MP. | The FLUX.2 editing docs describe multi-reference edits up to 10 images and output up to 4 MP. Confirm the live schema on that model page before you port a client. |
| Published price | $0.041 at 768sq, $0.048 at 1k, $0.100 at 2k, $0.607 at 4k, per image. 1.5k is not in the table. | Text-to-image from $0.03. Image editing from $0.045. Exact cost still depends on output megapixels. The page points at a calculator. |
| Try without code | playground.bfl.ai, linked from the FLUX 3 Image model page. | The same Playground hosts other FLUX models. Pick the model name in the UI. Do not assume a FLUX.2 session speaks FLUX 3 box JSON. |
| Best fit | Posters, panels, type with a fixed line, and edits that name what stays. | High-volume prompt edits where you do not want to author a box table. |
When to choose each
Choose FLUX 3 Image if a person or an agent must say where something sits. The model page's own example is an element table: an id, a box such as [10, 200, 170, 800], and a description, joined to one scene line. The API accepts that table only as the tail of prompt on POST /v1/flux-3-image. Local edits use keep, move, new, and remove rows, documented on the box guide. Pixels outside those boxes usually stay as they were. They are not a hard mask.
Choose FLUX.2 [pro] if the change is "recolor this jacket" or "put this product on that table" and you can say it in prose. The pricing page lists it as the production default for editing, from $0.045, against FLUX 3 Image at $0.048 for a roughly 1 megapixel frame before any launch discount a dashboard might still show. FLUX.2 [klein] 4B starts at $0.014 on the same page if cost matters more than the box format. Klein does not gain the FLUX 3 element table by being cheaper.
Do not mix the two clients. A body written for a reseller's boundingBoxes array, or for FLUX.2 input-image fields, will not validate on FLUX 3 Image, because that schema sets additionalProperties to false. Start from the layout guide, copy the curl shape, and read cost on the submit response. One credit is $0.01 on the pricing page, for both Playground and API.
What this comparison leaves out
It does not rank photorealism, text accuracy, or speed. Those numbers are not on the two doc pages used here. Open-weight timing is not stated on the FLUX 3 Image model page; that page only offers a commercial-weights conversation. FLUX.2 [dev] is listed as local weights and non-commercial, with no hosted API. If your constraint is self-hosting today, neither the FLUX 3 Image API nor this page solves it.