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Seedream 5.0 Lite, measured: 1K returns a 400, and where a flat price helps

A measured review of ByteDance Seed's Seedream 5.0 Lite — the flat $0.035 per image, the resolution floor that returns HTTP 400, and its failure to hold a referenced person.

AT A GLANCE

Check how Seedream 5.0 Lite handles references before relying on it for a recurring person. This review records measured fidelity, cost and latency and discusses suitable subjects.

On this page

Seedream 5.0 Lite's distinguishing feature is a per-image price you can predict: raising resolution does not change it. It also failed to hold a referenced person. The use cases divide cleanly.

Measured

ItemMeasured value
Latency~41s
Cost per image$0.035 (flat)
OutputJPEG
Measured on2026-08-28 (via OpenRouter)

It was the slowest of the three. The flat unit price does make monthly budgeting straightforward, which is a real advantage at volume.

The first trap: resolution=1K fails

Nano Banana 2 accepts 512 upward, so a shared UI listing one set of resolution options will break on Seedream alone. Accepted values have to be held per model.

Yui

1K is small, so surely it goes through?

Saki

The opposite. The floor is 3,686,400 pixels, so it is rejected for being too small.

Accepted parameters

ParameterAccepted values
Aspect ratioauto plus 18 options
Resolution2K / 4K (1K returns 400)
Images per run1–4
Reference imagesup to 14
Measured 2026-08-28.

Eighteen aspect ratios is the widest of the three models, which helps when you need an unusual frame.

Black Senpai

Don't use it to name a person. For anything else, a predictable price is worth a lot.

It did not hold identity

Given a reference, it returned a different person. It does reproduce style and mood, so a reference works as a tonal instruction — but not as "this specific person".

This is a property of the model, not something prompting fixes. Where identity matters, choose a different model up front.

Good for

  • Subjects without a person — backgrounds, objects, landscapes, abstracts
  • Budgeting against a fixed per-image cost
  • Unusual aspect ratios

Frequently asked questions

Can Seedream 5.0 Lite output 1K images?
Sending resolution=1K returns HTTP 400. A 3,686,400-pixel minimum applies, making 2K the floor.
What does it cost?
A flat $0.035 per image measured. Raising resolution does not change the unit price.
Can it keep the same person?
Not in our tests — a reference still produced a different person. Use GPT Image 2 when identity matters.
Written byunsketch Editorial

The unsketch editorial team benchmarks generative models under identical conditions and records latency, cost, and output behaviour. Every figure we publish is measured in-house.

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