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Image Model Comparison

Seedream 4.5 vs Flux Pro Ultra

ByteDance's 4K model vs Flux's 2K Ultra — high-resolution image generation compared.

Seedream 4.5 from ByteDance and Flux Pro Ultra from Black Forest Labs represent two different approaches to AI image generation. ByteDance's flagship model with stunning aesthetics and complex scene understanding. On the other side, ultra-high resolution (up to 2K) with enhanced photorealism and detail.

At 10 credits, Seedream 4.5 costs 10 credits less than Flux Pro Ultra (20 credits). The question is whether the extra cost of Flux Pro Ultra translates into meaningfully better results for your use case. For artistic scenes, complex compositions, high-resolution output, Seedream 4.5 is hard to beat at its price point. But if you need large-format prints, posters, cinematic stills, photorealistic output, Flux Pro Ultra may justify the premium.

Updated March 2026

The Bottom Line

Flux Pro Ultra costs 10 credits more per generation — that adds up fast. Start with Seedream 4.5 for most work. It handles artistic scenes, complex compositions, high-resolution output well. Save Flux Pro Ultra for when you specifically need large-format prints and the quality difference matters.

Seedream 4.5 vs Flux Pro Ultra: Visual Output

Both generated with the same prompt and seed 42. Click to view full size.

ByteDanceSeedream 4.5
Black Forest LabsFlux Pro Ultra

Seedream 4.5 vs Flux Pro Ultra: How They Compare

ByteDanceSeedream 4.5
Black Forest LabsFlux Pro Ultra
ProviderByteDanceBlack Forest Labs
ReleasedDec 2025Nov 2024
Cost
10
20
SpeedMediumSlower
Reference imagesUp to 10Up to 1
Editing

Seedream 4.5 vs Flux Pro Ultra: Cost Comparison

Seedream 4.5 is 50% cheaper than Flux Pro Ultra. Here's how credits add up at scale.

VolumeSeedream 4.5Flux Pro Ultra
10 images 100 200
50 images 500 1,000
100 images 1,000 2,000

Strengths & Weaknesses

ByteDance

Seedream 4.5

Strengths
  • + More affordable (10 vs 20 credits)
  • + Artistic scenes
  • + Supports 10 reference images
  • + Built-in image editing
  • + More resolution options
Weaknesses
  • - Higher price point relative to speed tier
Black Forest Labs

Flux Pro Ultra

Strengths
  • + Large-format prints
  • + Raw mode for unprocessed output
  • + Reference image with strength control
  • + Prompt enhancement
  • + Up to 2K resolution
Weaknesses
  • - More expensive (20 vs 10 credits)
  • - Slower generation
  • - No built-in editing

Seedream 4.5 vs Flux Pro Ultra: Which to Pick?

On a tight budget

At 10 credits per image, Seedream 4.5 gives you more generations for your plan. Good enough quality for most everyday use.

Seedream 4.5

Maximum quality matters

Flux Pro Ultra is worth the extra credits when the output needs to be perfect — portfolio pieces, client work, or final deliverables.

Flux Pro Ultra

Character or style consistency

Seedream 4.5 supports 10 reference images to keep subjects, styles, and characters consistent across generations.

Seedream 4.5

Editing existing images

Seedream 4.5's built-in editing lets you refine and modify images with prompt-driven changes instead of starting from scratch.

Seedream 4.5

Seedream 4.5 vs Flux Pro Ultra: FAQ

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