Seedream 4 vs 4.5 vs 5 Lite on Sume: price, ratios, auto

Seedream 4, Seedream 4.5 and Seedream 5 Lite are all in the Sume image catalog, and they differ in two places that matter for a pipeline: price and the aspect_ratio list. Seedream 4 is the cheapest at 0.0325 USD and the only one of the three that lists auto; Seedream 5 Lite is 0.04375 USD; Seedream 4.5 is 0.05 USD.

All three take up to 10 references, return 1 to 4 images per call and offer png, jpeg and webp. I compare only what the catalog states, not image quality, because the Sume docs publish no benchmark of the three.

Side by side

The values come from the capability descriptors and endpoint pricing in the Sume image catalog, read on 2026-10-10. Prices are the base price per image.

What the ratio lists mean

The nine ratios are the same on all three: 1:1, 16:9, 9:16, 4:3, 3:4, 4:5, 5:4, 3:2 and 2:3. Only Seedream 4 adds auto. On an edit, auto matches the reference image, and the Image API docs say that omitting the field is not the same thing.

If you move an edit flow from Seedream 4 to 4.5 or 5 Lite and still send aspect_ratio: "auto", Sume answers 400 invalid_request and lists the accepted values in details.supported. Change the code to send a fixed ratio computed from the source image.

Cost of a batch

A 12-image batch at base price costs 12 x 0.0325 = 0.39 USD on Seedream 4, 12 x 0.04375 = 0.525 USD on Seedream 5 Lite, and 12 x 0.05 = 0.60 USD on Seedream 4.5. The spread between the cheapest and the dearest is 0.21 USD for twelve images, so the choice is mostly about whether the output quality matters to you, which you have to judge on your own samples.

Failed and cancelled generations are not billed, so a re-run after an error does not double the figure.

Where the three sit among other editors

Seedream is not the only low-cost reference-capable family in the catalog. FLUX.2 Pro takes up to 10 references at 0.0375 USD, and Qwen Image takes up to 10 at 0.025 USD, so Seedream 4 at 0.0325 USD sits between them on price. Neither FLUX.2 Pro nor Qwen Image lists auto, which makes Seedream 4 the cheap option that keeps the source shape by itself.

Seedream 4.5 and 5 Lite cost more than FLUX.2 Pro and do not list auto, so pick them for their own look and not for convenience. Because the Sume docs make no quality claim between these families, the only fair way to choose is a side-by-side run on your own images, which at these prices costs a few cents.

How to choose

Make the decision on what your request needs, then on price. The sequence below keeps the choice honest:

• If the edit must match the source shape with no ratio math, use Seedream 4.
• If you need the newest of the three, use 5 Lite or 4.5 and compute the ratio in code.
• Run the same five prompts on all three and compare the results yourself before you commit a batch.
• Pin the exact model id in your code and read the catalog at start-up so a change shows up as an error, not as a surprise.