Seedream 5.0 Lite vs Nano Banana Pro vs GPT Image 1.5: AI Image API Compared

We tested all three through the EvoLink API with identical prompts, measured latency, compared output quality, and calculated real-world costs. Here's what we found.

The Three Contenders

All three produce stunning images from text. All three support reference images, high resolutions, and API-first workflows. But they're not interchangeable — each has strengths that make it the obvious pick for certain tasks.

Seedream 5.0 Lite: The Thinker

Seedream 5.0 Lite is a unified multimodal system — it doesn't just generate images, it understands and reasons about them. Images tend to be compositionally sophisticated, with accurate spatial relationships and strong scene logic.

Nano Banana Pro: The Photographer

It's also the fastest of the three, which matters for high-volume pipelines. The editing capabilities are particularly strong: inpainting and outpainting feel natural, and context preservation around edited regions is best-in-class.

GPT Image 1.5: The Listener

This makes it the safest choice for automated pipelines where prompts are generated programmatically. The tiered quality system (low/medium/high) gives you fine-grained cost-quality control per request.

Image Quality & Style

• Seedream 5.0 Lite — Compositionally sophisticated, excellent for technical and knowledge-rich scenes. Deep Thinking mode produces fewer errors on complex prompts.
• Nano Banana Pro — Best overall photorealism. Strongest for product shots, lifestyle imagery, and anything requiring a "this looks like a real photo" result.
• GPT Image 1.5 — Most consistent at following detailed visual specs. Ideal when prompts are generated programmatically and must be executed precisely.

Text Rendering in Images

GPT Image 1.5 is a close second for English text rendering, producing legible signs, labels, and short phrases reliably.

Unique Capabilities

Seedream 5.0 Lite: Deep Thinking + Web Search

Two features set Seedream 5.0 Lite apart from every other image generation model:

• Deep Thinking — Before generating, Seedream 5.0 Lite engages a reasoning step that analyzes the prompt, identifies ambiguities, and plans composition. Think chain-of-thought reasoning applied to visual generation. The result: noticeably better complex scenes, spatial relationships, and technical accuracy.
• Online Web Search — Seedream 5.0 Lite can fetch real-time information from the web during generation. Ask for "the latest iPhone model on a desk" and it pulls in up-to-date visual references. No other image model does this natively.

Nano Banana Pro: Editing Powerhouse

Nano Banana Pro's editing capabilities go beyond simple inpainting. The model understands semantic edits from plain language: "remove the glare," "swap the mug for a glass," "change the background to a beach at sunset." It applies changes while preserving the rest of the scene with remarkable consistency.

For teams running high-volume content operations — localizing ad creatives across markets, refreshing product photography seasonally, or generating A/B test variants — this editing-first approach saves enormous amounts of time.

Reference Image Support

• Seedream 5.0 Lite: Up to 14 references — best for identity preservation across series, brand consistency
• Nano Banana Pro: Up to 14 references — best for character/product consistency, catalog generation
• GPT Image 1.5: Up to 10 references — best for style transfer, composition guidance

API Integration & Speed

import requests

EVOLINK_API_KEY = "your-api-key"
BASE_URL = "https://api.evolink.ai/v1/images/generations"

headers = {
    "Authorization": f"Bearer {EVOLINK_API_KEY}",
    "Content-Type": "application/json"
}

seedream    = {"model": "doubao-seedream-5.0-lite",  "prompt": "...", "size": "1024x1024"}
nano_banana = {"model": "nano-banana-pro",    "prompt": "...", "size": "1024x1024"}
gpt_image   = {"model": "gpt-image-1.5",     "prompt": "...", "size": "1024x1024", "quality": "medium"}

response = requests.post(BASE_URL, headers=headers, json=seedream)
print(response.status_code, response.text)

Pricing on EvoLink

Real costs for 1,000 images:

GPT Image 1.5 is the clear budget winner. But price isn’t everything — Nano Banana Pro’s photorealism at $0.04/image can save significant retouching time, while Seedream 5.0 Lite at $0.03/image offers the best value for knowledge-rich content.

Combined with tiered quality, this makes GPT Image 1.5 ideal for cost-sensitive, high-volume pipelines. Generate thumbnails at "low" quality for $0.007 each, then switch to "high" for hero images — same endpoint.

When to Use Which

Choose Seedream 5.0 Lite when:

• You need real-time information in images (news, current events, up-to-date products)
• Prompts require reasoning (scientific diagrams, complex layouts, data visualization)
• Accuracy > speed
• Maximum reference images matter (14 refs for brand consistency)

Choose Nano Banana Pro when:

• Photorealism is non-negotiable (product shots, lifestyle imagery)
• Image editing is part of your workflow (inpainting, outpainting, object swaps)
• Volume > 10,000 images/month
• You need fast turnaround (3–6 seconds)
• Multi-language text rendering (global marketing)

Choose GPT Image 1.5 when:

• Budget is the primary constraint ($0.007/image)
• Instruction following must be rock-solid (automated pipelines)
• You need tiered quality control (low for drafts, high for finals)

• Social media thumbnails → GPT Image 1.5
• Product catalog → Nano Banana Pro
• Hero marketing images → Nano Banana Pro
• Scientific posters → Seedream 5.0 Lite
• Blog illustrations → Seedream 5.0 Lite
• A/B test variants → GPT Image 1.5 (low quality, high volume)

The EvoLink Advantage: Don't Choose — Route

The real power move is using all three through EvoLink's unified API. One API key. One bill. Route each request to the best model for that specific task.

EvoLink gives you unified API access to Seedream 5.0 Lite, Nano Banana Pro, GPT Image 1.5, and 40+ AI models — one API key, one endpoint, one bill.

• ✅ One API key for all image, video, text, and audio models
• ✅ No subscription — pay only for what you generate
• ✅ Save up to 94% vs official API pricing

The Bottom Line

• Seedream 5.0 Lite wins on intelligence — Deep Thinking, web search, and scientific accuracy.
• Nano Banana Pro wins on realism — if it needs to look like a photograph, this is your model.
• GPT Image 1.5 wins on value — $0.007/image with rock-solid instruction following.

The real winner? Using all three through EvoLink — one API key, one bill, and the freedom to route each request to the best model for the task. Stop choosing. Start routing.

Start Building with EvoLink

FAQ

What is the best AI image generation API in 2026?

There's no single best — it depends on your use case. Seedream 5.0 Lite leads for knowledge-rich and scientific images with its Deep Thinking and web search. Nano Banana Pro is the photorealism champion with the fastest speed. GPT Image 1.5 offers the best value at $0.007/image with strong instruction following. EvoLink lets you use all three with one API key.

Does Seedream 5.0 Lite really search the web during image generation?

Yes. Seedream 5.0 Lite's Online Web Search fetches real-time information during generation — current events, up-to-date product designs, recent public figures. No other image model does this natively.

How much does Seedream 5.0 Lite cost compared to Nano Banana Pro and GPT Image 1.5?

On EvoLink: GPT Image 1.5 from $0.007/img (cheapest), Seedream 5.0 Lite from $0.03/img, Nano Banana Pro from $0.04/img. For 1,000 images: $7 / $30 / $40 respectively.

Which AI image API is cheapest in 2026?

On EvoLink, GPT Image 1.5 is the cheapest at $0.007/image — vs official $0.009/image. Seedream 5.0 Lite at $0.03/image (official $0.35), and Nano Banana Pro at $0.04/image (official $0.15).

Which model is best for e-commerce product photography?

Nano Banana Pro is the strongest choice — superior photorealism, fast generation, and powerful editing. For budget-conscious teams generating large volumes, GPT Image 1.5 offers a compelling cost-quality tradeoff.

Is Seedream 5.0 Lite good for marketing and advertising?

Yes. Seedream 5.0 Lite excels at generating marketing materials that require factual accuracy — product posters with real specifications, data-driven infographics, and campaign visuals that reference current trends (via web search). For pure photorealistic product shots, Nano Banana Pro may be a better fit; for high-volume social media assets on a budget, GPT Image 1.5 is more cost-effective. All three are available on EvoLink.

What models are similar to Seedream 5.0 Lite?

The closest competitors to Seedream 5.0 Lite are Nano Banana Pro (Google's Gemini 3 Pro Image — best for photorealism), GPT Image 1.5 (OpenAI — best for instruction following and budget generation), and Flux 2 (open-weight alternative). Seedream 5.0 Lite's unique advantages are Deep Thinking reasoning and real-time web search — no other image model offers these natively. EvoLink provides API access to all of these models through a single endpoint.

What is the difference between Seedream 5.0 Lite and Seedream 4.5?

Seedream 5.0 Lite adds two major capabilities over Seedream 4.5: Deep Thinking (reasoning before generation for complex prompts) and Online Web Search (fetching real-time information during generation). It also supports up to 14 reference images (vs 10 in 4.5) and delivers improved accuracy for scientific, technical, and knowledge-based images.