Seedream 5.5 variants & parameters
| Parameter | Seedream 5.5 Pro | Seedream 5.5 Pro-N |
|---|---|---|
| Duration | — | — |
| Aspect ratios | 1:1 · 16:9 · 9:16 · 4:3 · 3:4 · 3:2 · 2:3 · 21:9 · 9:21 | 1:1 · 16:9 · 9:16 · 4:3 · 3:4 · 3:2 · 2:3 · 21:9 · 9:21 |
| Resolution | — | — |
| Native audio | — | — |
| Image-to-video | — | — |
| Reference-to-video | — | — |
| Credits per second | — | — |
| 5-second clip cost | 2 cr/image | 2 cr/image |
What is Seedream 5.5?
Seedream 5.5 is the newest generation of ByteDance's Seedream image model, added to FlyAIgh in November 2026. It handles both text-to-image and image editing: write a prompt on its own, or add one to ten reference images to restyle a photo, keep a product or character while changing the scene, or merge several images into one.
FlyAIgh offers it in two lines with the same settings and the same price. **Seedream 5.5 Pro** and **Seedream 5.5 Pro-N** reach the model through two separate supplier routes; pick either, and if one is slow or returns an error, the other is a second route to the same generation. Neither line costs more than the other.
Output comes in two sizes. **1K** is about one megapixel — 1024 × 1024 for a square — and **2K** is about four megapixels, 2048 × 2048 for a square. Nine aspect ratios are available, from 1:1, 4:3 and 3:2 through 16:9 and the ultrawide 21:9, plus their vertical versions; we size every ratio to the same pixel budget, so a 16:9 image at 2K is 2736 × 1536.
The standout addition is a **native transparent background**. Turn it on and Seedream 5.5 returns a PNG with an alpha channel, whether you start from a text prompt or from reference images — useful for logos, stickers, product cut-outs and design assets you want to drop onto any background. With it off, the image comes back as an ordinary JPEG.
Without reference images the price depends only on the size: 2 credits per image at 1K and 3 credits at 2K. Reference images add about half a credit each, rounded up per image — one reference costs nothing extra, ten bring 1K to 7 credits and 2K to 8 — because the supplier bills every reference it reads. Aspect ratio and the transparent background never change the price. The supplier generates one image per request and does not offer group images or web search, so each run is a single picture.
Compared with Seedream 5.0 Pro, 5.5 costs less for text-to-image and light edits (2 and 3 credits against 3 and 5), accepts ten reference images instead of six, and adds the transparent background. Seedream 5.0 Lite and Pro keep their own page. Like every model on FlyAIgh, Seedream 5.5 runs on the same credit wallet, with no ByteDance account or API key.
Seedream 5.5 vs Seedream 5.0 vs Nano Banana
| Capability | Seedream 5.5 | Seedream 5.0 | Nano Banana |
|---|---|---|---|
| Native audio | |||
| Image-to-video | |||
| Reference-to-video | |||
| First/last frame |