Short version: if you only ever render at 1K, Seedream 5.0 Pro is a hair cheaper and gives you cleaner, catalog-ready images. If you want 2K, Nano Banana Pro is the better deal — it charges the same for 2K as it does for 1K, and it is the only one of the two that goes to 4K. Both are flagship image models you can call through a single HiAPI key, so this is a choice between two models, not two vendors.
To keep it honest, I ran the same three prompts through both models at 2K, looked at every output, and wrote down what I actually saw. No scores, no benchmarks I can't show you — just matched pairs and the price math that goes with them.
Price: where each one actually wins
Prices below are from the live HiAPI pricing API as of October 2026. Check the pricing page before you budget — these move.
| Resolution | Seedream 5.0 Pro (text-to-image) | Nano Banana Pro |
|---|---|---|
| 1K | $0.05 / image | $0.057 / image |
| 2K | $0.10 / image | $0.057 / image |
| 4K | not available | $0.10 / image |
Two things fall out of this:
- At 1K, Seedream is cheaper, but only by $0.007 per image. On a run of 1,000 images that is $7. Real, but small.
- At 2K, Nano Banana Pro is cheaper by a wide margin — $0.057 vs $0.10, roughly 43% less. Nano Banana Pro charges the same for 2K as for 1K, so there is no reason to downscale it to save money. Seedream doubles its price to step up to 2K.
- Only Nano Banana Pro reaches 4K (a smart-upscale step on top of its 2K render), at $0.10 — the same price Seedream charges just to get to 2K. If you need print-scale output, that is the single biggest practical difference.
Seedream 5.0 Pro also has a separate image-to-image route at $0.06 (1K) / $0.10 (2K) that accepts up to 10 reference images. Nano Banana Pro supports image editing as well; see its model page for the exact request shape.
Round 1: In-image text
Both models market their text rendering, so I made them render the same café chalkboard. Same prompt, both at 16:9 2K:
A weathered wooden A-frame chalkboard sidewalk sign outside a cozy cafe in soft morning light, the chalkboard clearly reads 'MORNING BREW' on the first line and 'Single-Origin Pour-Over 4.50' below it in neat hand-lettered chalk typography, blurred brick storefront behind, shallow depth of field, photorealistic, warm tones
Seedream 5.0 Pro:
Nano Banana Pro:
Both spelled every word correctly — "MORNING BREW" and "Single-Origin Pour-Over 4.50", no dropped letters or garbling. The difference is style, not accuracy. Seedream went literal and clean: plain sans-serif chalk, bright daytime light, easy to read. Nano Banana Pro went art-directed: ornate Victorian display lettering and a flowing script for the price line, warmer golden-hour light, and a richer street scene behind the board. If you need a board a customer could actually copy, both work. If you want something that already looks like a brand mood board, Nano Banana Pro did more of that work for you here.
Round 2: E-commerce product shots
The e-commerce test: a frosted serum bottle with a readable label. Same prompt, both at 1:1 2K:
Photorealistic studio product photograph of a frosted glass skincare serum bottle with a matte dropper cap, a clean minimalist front label printed with the word 'LUMA' on top and a thin subtitle 'Hydrating Serum' below it, standing on a wet dark slate surface with scattered water droplets, soft diffused overhead studio lighting, gentle reflection, deep shadows, luxury cosmetics advertising, ultra detailed
Seedream 5.0 Pro:
Nano Banana Pro:
Again both rendered "LUMA" and "Hydrating Serum" cleanly. The look split the same way it did in Round 1. Seedream gave me a bright, high-key catalog shot — the kind of crisp, near-cutout image you drop straight onto a product page. Nano Banana Pro gave me a moody, warm editorial scene: background jars for depth, a wet reflection of the label on the stone (it even rendered the mirrored text), and cinematic shallow focus. For a marketplace listing that needs a clean white-ish background, Seedream needed less reworking. For an ad or a brand hero, Nano Banana Pro's version is closer to finished.
Round 3: Portraits and fine detail
For skin, hair, and atmosphere I used a weathered fisherman. Same prompt, both at 3:4 2K:
A cinematic close-up portrait of a weathered elderly fisherman with a thick white beard and deep wrinkles, wearing a bright yellow rain hood, standing at a foggy harbor at dawn, tiny water droplets clinging to his beard and skin, soft directional light from the left, shallow depth of field, hyper-detailed, photorealistic
Seedream 5.0 Pro:
Nano Banana Pro:
This was the closest round. Both are genuinely photorealistic down to the pores and individual beard hairs, and both held the water-droplet detail. Seedream leaned cinematic: a polished, warmly lit, shallow-focus portrait that looks produced. Nano Banana Pro leaned documentary: flatter natural overcast light, the full harbor and dock sharp behind him, the kind of frame that reads like a candid photo someone actually took. Neither is "better" — they are two different photographic intentions from the same words.
Parameters and API: what you pass
Both models run on HiAPI's async task API (POST /v1/tasks, then poll), so the calling pattern is identical; only the input fields differ.
- Seedream 5.0 Pro (text-to-image):
prompt,aspect_ratio(8 options including 21:9), andresolution(1Kor2K) are required, with an optionaloutput_format. The image-to-image route adds animage_urlsarray of up to 10 references. - Nano Banana Pro:
promptplusaspect_ratio(1:1, 16:9, 9:16, 4:3, 3:4) and a resolution up to 2K, with a smart 4K upscale available on top. It also supports image editing.
For the full, current field list and defaults, open each model page — that is the source that stays in sync with the API.
When to choose each
Choose Seedream 5.0 Pro when:
- You render mostly at 1K and want the lowest per-image price.
- You want clean, literal, catalog-style output that needs little retouching.
- You need wide aspect ratios like 21:9, or multi-reference image-to-image with up to 10 inputs.
Choose Nano Banana Pro when:
- You render at 2K — you get it at the 1K price, and far cheaper than Seedream's 2K.
- You need 4K output for print or large displays (Seedream 5.0 Pro stops at 2K).
- You want a more art-directed, editorial look out of the box for ads and brand heroes.
The honest answer for a lot of teams is "run both." Because they share one API key, you can send the same prompt to each and pick the winner per image — which is exactly how the pairs above were made.
FAQ
Which is cheaper, Seedream 5.0 Pro or Nano Banana Pro? It depends on resolution. At 1K, Seedream is cheaper ($0.05 vs $0.057). At 2K, Nano Banana Pro is cheaper ($0.057 vs $0.10). Only Nano Banana Pro offers 4K, at $0.10.
Do both render text accurately? In my three tests both spelled every word on the signage and labels correctly. They differ in typography style, not spelling — Seedream is plainer, Nano Banana Pro is more decorative. Always proof your own output before shipping it.
Which one is better for e-commerce product images? Seedream 5.0 Pro gave the cleaner, catalog-ready shot with less background to remove. Nano Banana Pro gave a moodier editorial frame that suits ads more than plain listings.
Can I use one API key for both?
Yes. Both are on HiAPI's unified task API, so a single key and the same POST /v1/tasks pattern call either model — only the input fields change.
Is 4K on Nano Banana Pro true 4K? It is a smart upscale applied on top of a native 2K render, priced at $0.10. Seedream 5.0 Pro does not offer a 4K tier at all.
Key takeaways
Pick Seedream 5.0 Pro for cheap, clean 1K work and for 21:9 or multi-reference editing. Pick Nano Banana Pro for affordable 2K, for 4K output, and for a more finished editorial look. Both are flagship-grade and text-accurate; the real decision is resolution budget and visual direction. Spin up a key, send one prompt to each, and let the outputs decide.
Ready to test them yourself? Open the Seedream 5.0 Pro and Nano Banana Pro model pages and run the same prompt through both with one HiAPI key.
