Seedream 4.5 vs Seedream 5.0 Lite
Which one, when — curated verdict, not a benchmark table
The newer seedream-5-0-260128 is also the cheaper one, $0.035 per call against $0.04, and it widens output to 2K/3K/4K with custom sizes from 2560x1440 up to 4096x4096 at ratios to 16:1, where seedream-4-5-251128 offers 2K and 4K only. It also returns png as well as jpeg. Reference handling is identical — 2–14 references, up to 15 images per request — so there is no case for the older model beyond reproducing output you already shipped.
Pricing
| Seedream 4.5 | Seedream 5.0 Lite | Δ | |
|---|---|---|---|
| Per generated image | $0.04 | $0.035 | 1.1× |
Rates from the live catalog at build time; each model page carries the current card.
Where they sit — price per generated image across all 8 image-generation models on this billing unit (log scale)
Specs
| Seedream 4.5 | Seedream 5.0 Lite | |
|---|---|---|
| Input modalities | text image | text image |
| Output modalities | image | image |
| Released | 2025-12 | 2026-01 |
| Output sizes |
|
|
| Input modes | text-to-image, single-image image-to-image, multi-reference image-to-image (2–14 refs), batch/sequential image sets | text-to-image, single-image image-to-image, multi-reference image-to-image (2–14 refs), batch/sequential image sets |
| Images per request | 15 | 15 |
| Formats | jpeg | png, jpeg |
| Notes | 2K/4K output, jpeg text-to-image, single and multi-reference image-to-image, batch generation improved text rendering and multi-image consistency 500 max IPM | 2K/3K/4K output, png/jpeg text-to-image + single/multi-reference image editing batch generation with reference + generated images <=15 500 max IPM |
Specs are transcribed from each vendor’s documentation; a row a vendor does not publish is left out rather than inferred. Full sources: Seedream 4.5 · Seedream 5.0 Lite
One prompt, both models — measured through the gateway
One prompt, one request per model, no retries and no cherry-picking — the first result each model returned. Neither size nor duration was pinned: each model used its own default, because a request shaped to fit all of them would flatter none. Files here are re-encoded for the web, so judge composition and prompt adherence, not compression.
Switch between them with one line
Both ids are in every tab below — the highlighted pair of lines is the only edit. Same endpoint, same key, same request shape.
from openai import OpenAI
client = OpenAI(
base_url="https://synthorai.io/v1",
api_key="sk-syn-...",
)
resp = client.images.generate(
model="seedream-4-5-251128",
# model="seedream-5-0-260128", # uncomment this line, comment the one above
prompt="a watercolor lighthouse at dawn",
size="1024x1024",
)
print(resp.data[0].b64_json[:80])import OpenAI from "openai";
const client = new OpenAI({
baseURL: "https://synthorai.io/v1",
apiKey: "sk-syn-...",
});
const resp = await client.images.generate({
model: "seedream-4-5-251128",
// model: "seedream-5-0-260128", // uncomment this line, comment the one above
prompt: "a watercolor lighthouse at dawn",
size: "1024x1024",
});
console.log(resp.data?.[0]?.b64_json?.slice(0, 80));curl https://synthorai.io/v1/images/generations \
-H "Authorization: Bearer sk-syn-..." \
-H "Content-Type: application/json" \
-d '{
"model": "seedream-4-5-251128",
# "model": "seedream-5-0-260128", # uncomment this line, comment the one above
"prompt": "a watercolor lighthouse at dawn",
"size": "1024x1024"
}'package main
import (
"context"
"fmt"
"github.com/openai/openai-go/v3"
"github.com/openai/openai-go/v3/option"
)
func main() {
client := openai.NewClient(
option.WithBaseURL("https://synthorai.io/v1"),
option.WithAPIKey("sk-syn-..."),
)
resp, _ := client.Images.Generate(context.TODO(), openai.ImageGenerateParams{
Model: "seedream-4-5-251128",
// Model: "seedream-5-0-260128", // uncomment this line, comment the one above
Prompt: "a watercolor lighthouse at dawn",
Size: "1024x1024",
})
fmt.Println(resp.Data[0].B64JSON[:80])
}import com.openai.client.OpenAIClient;
import com.openai.client.okhttp.OpenAIOkHttpClient;
import com.openai.models.images.*;
OpenAIClient client = OpenAIOkHttpClient.builder()
.baseUrl("https://synthorai.io/v1")
.apiKey("sk-syn-...")
.build();
ImagesResponse resp = client.images().generate(
ImageGenerateParams.builder()
.model("seedream-4-5-251128")
// .model("seedream-5-0-260128") // uncomment this line, comment the one above
.prompt("a watercolor lighthouse at dawn")
.size("1024x1024")
.build());
System.out.println(resp.data().orElseThrow().get(0).b64Json().orElseThrow().substring(0, 80));FAQ
Which is cheaper, Seedream 4.5 or Seedream 5.0 Lite?
Seedream 5.0 Lite is cheaper on per generated image ($0.035 vs $0.04, 1.1× apart). Other rows may point the other way — the table above carries the full card, and real cost depends on your mix.
Can I A/B test Seedream 4.5 against Seedream 5.0 Lite without two integrations?
Yes. Both are served through the same OpenAI-compatible endpoint with one API key — switching is a one-line model-string change, so you can route a fraction of traffic to each and compare bills directly.
Does the price change with image size?
It depends on how the model bills. Per-image models charge the same regardless of prompt or output size; token-billed models scale with the resolution you render, so a 4K image costs a multiple of a small one. The table above shows which applies to each.