FLUX vs Seedream (2026): FLUX.2 Pro vs Seedream 5 Pro, Tested

For literal action and process shots, FLUX.2 Pro won our test, and its successor in Masonry is FLUX 3 Image (not yet tested here): in our ceramic-artist test FLUX.2 Pro put the subject at the wheel with a visibly unfinished vase, as the brief asked. For a polished, posed editorial portrait, or when you start from reference images, use Seedream 5 Pro: it made the cleaner portrait, and its current Masonry route accepts up to ten references. Short label text is a tie: both rendered all three label lines exactly.

The old answer, FLUX for realism and Seedream for text, no longer holds for the current pair. On the product brief both passed the text test and invented different bottle geometry, with FLUX rendering more complex glass, pump and stone surfaces. On the portrait brief Seedream placed the artist at a worktable beside a more finished, decorated vase. Both images are strong; only one followed that action brief closely.

Quick verdict

• Best for literal action and process staging: FLUX.2 Pro. It put the artist at the wheel with an unfinished vase.
• Best for a polished, posed editorial portrait: Seedream 5 Pro. The cleaner composition, though it turned the scene into a paused portrait.
• Best for reference-led generation in the current Masonry CLI: Seedream 5 Pro, with up to ten references. FLUX.2 Pro was text-only when we tested, and Masonry has since replaced it with FLUX 3 Image, which also takes up to ten references. We have not compared their reference handling.
• Exact short label text: tie in this one-prompt sample. Both returned all three lines with the requested spelling and order.
• Open weights: neither Pro model. FLUX.2 has separate open-weight variants, but they are not the FLUX.2 Pro endpoint tested here.

How we tested: one controlled same-prompt output per model per brief at 1024 × 1024, with matched seeds and no reference images, so these are task-level picks, not a universal winner.

How the test was run

I generated the files on August 4, 2026 through the logged-in Masonry CLI:

• Same prompt within each test
• Same requested 1024 × 1024 dimensions
• Same seed within each test: 42817 for product, 90214 for portrait
• Prompt enhancement off
• No input or reference images
• First successful size-matched output retained; earlier Seedream default-size runs were excluded because they were 1536 × 1536

The final files are shown unedited except for responsive delivery by Masonry's media CDN. The model names in each caption are the models that generated them.

Test 1: exact label text on a fictional product

Square editorial product photograph of a fictional cobalt-blue glass skincare pump bottle standing on warm travertine, soft window light from camera-left, one eucalyptus shadow on the wall, premium but physically plausible materials. The bottle label must show exactly three centered lines: ALBA, NIGHT REPAIR, 30 ML. Front-facing bottle, label fully readable, no other text, no extra bottles, no logo.

FLUX.2 Pro output

Seedream 5 Pro output

What the files show: both models passed the short-text requirement. FLUX rendered more complex glass, pump, and stone surfaces. Seedream made the botanical shadow more prominent and the composition more graphic. Neither can be called product-faithful because the brief described a fictional bottle without a source photo; each was free to invent the package.

Verdict for this test: tie on the requested text. Pick by the surface treatment you prefer, then test several more labels before trusting either model with production typography. For a real SKU, use a consented source image and reject any output that changes its shape, closure, label, color, or included claims.

If the bottle has to match a product you actually sell, this fictional-package test is not the decision. Run both routes against the same approved source in the same-SKU product-photo fidelity test, lock the product invariants before generation, and compare accepted files rather than attractive inventions.

Test 2: candid ceramic-artist process portrait

Square candid 35mm editorial photograph of an adult ceramic artist in a sunlit working studio, seated beside a half-finished stoneware vase, rust linen apron over a charcoal shirt, both hands visible with a light dusting of clay, natural skin texture, flyaway hair, shelves of irregular handmade bowls softly out of focus, side window light, realistic color, no beauty retouching, no text, no extra fingers.

FLUX.2 Pro output

Seedream 5 Pro output

What the files show: FLUX interpreted “half-finished” and “working studio” as an active wheel scene. Seedream followed the wardrobe, light, shelves, hands, and studio context but made the vase look finished and decorated. Seedream's face is softer and the subject placement more editorial; FLUX's process story is clearer.

Verdict for this test: FLUX followed the action brief more literally. Seedream made a strong image, but it changed the moment. If the subject must be performing a specific action, that difference is a rejection criterion, not an aesthetic preference.

Current Masonry contract: do not confuse the family with the route

These parameter contracts were rechecked with masonry models info on November 1, 2026 (the test above ran on the August 4 routes). In November 2026 Masonry replaced FLUX.2 Pro with FLUX 3 Image, so the FLUX.2 Pro column is a record of the tested route:

Black Forest Labs' own FLUX.2 documentation describes broader editing and multi-reference support across its provider endpoints, and its current output guide documents FLUX.2 output up to four megapixels. That does not change what the current Masonry flux-2-pro adapter accepts. Check the contract you will actually call.

The old article also treated “FLUX has open weights” as a property of FLUX Pro. That is incorrect. FLUX.2 Pro is hosted. The broader family includes FLUX.2 klein, whose 4B variant is Apache 2.0, and FLUX.2 dev under Black Forest Labs' non-commercial license. Do not transfer a Pro quality result to a different open-weight model.

Reproduce the test from the CLI

Run masonry models params flux-3-image and masonry models params seedream-5-pro first. Then keep prompt, dimensions, and seed fixed:

The CLI returns a job ID. Download each result with the masonry job download command it prints. Keep the raw files, prompt, model slug, dimensions, seed, run date, and rejection notes together so the comparison remains auditable.

Score accepted images, not attractive images

Use the same acceptance sheet before looking at the model name:

Generate the same number of candidates per model and calculate acceptance rate. Then divide the credits spent by accepted images. That quotient is the cost per accepted image. A cheaper generation that fails the label or action brief has no production value.

Which one should you use?

• Use FLUX.2 Pro first when literal action staging, surface detail, or a fixed production endpoint matters. In these files it followed the process portrait more closely.
• Use Seedream 5 Pro first when your workflow starts from reference images or needs a polished posed look. For FLUX in Masonry today, use FLUX 3 Image.
• Run both when the image is expensive to get wrong. The product test shows why: both satisfied the written requirement, but they made different creative decisions that a spec sheet cannot rank for your brand.

This article replaces a legacy FLUX 1.1 Pro versus Seedream 4 spec comparison. Those models remain available, but they are not the current pair tested here. For a broader cross-model view, see the product-photography model roundup, the text-rendering comparison, and GPT Image 2 vs FLUX.2.