What image generation actually costs: measured prices, and the setting that multiplies them by seven

4 min read

Image generation pricing is usually quoted as a single per-image number. In practice the same model can cost several times more depending on one setting. Everything below is what we were actually billed.

Per-image cost at default settings

ModelCost per imageLatencyImages per runOutput
GPT Image 2$0.0174–0.0229 (~$0.019)~24s1–10PNG
Nano Banana 2$0.068~11s1 onlyJPEG
Seedream 5.0 Lite$0.035 (flat)~41s1–4JPEG
Measured 2026-08-28 via OpenRouter.

Under these conditions GPT Image 2 is cheapest and Nano Banana 2 dearest, with latency running in the opposite order. Faster costs more, straightforwardly.

Raising quality multiplies cost by nearly seven

GPT Image 2 exposes a quality parameter (auto / low / medium / high). The $0.019 above is at auto. Running the same model at 16:9 and quality=high produced this:

SettingsCostLatency
auto / 1:1~$0.019~24s
high / 16:9$0.129972.3s
GPT Image 2. Top row measured 2026-08-28, bottom row 2026-08-31.
Yui

Can't I just compare the per-image price?

Saki

You rarely accept the first output. What matters is how many runs it takes to get a keeper.

Budget per accepted image, not per run

You rarely accept the first output. Real cost is set by how many runs it takes to get one keeper — which is where images-per-run matters.

Nano Banana 2 emits one image per run, so seeing five candidates costs five runs and $0.34. GPT Image 2 emits up to ten per run, so five candidates cost about $0.095. The headline per-image gap is 3.6×; including selection it widens.

To see five candidatesRunsTotal cost
GPT Image 21 (five at once)~$0.095
Nano Banana 25$0.34
Seedream 5.0 Lite2 (4 + 1)$0.07
Derived from each model's per-run image cap and the measured unit costs above.

Resolution affects whether the call succeeds, not what it costs

Seedream 5.0 Lite is a flat $0.035 per image; raising resolution does not change the unit price. It does, however, have a floor.

GPT Image 2 has no resolution parameter at all — it is unsupported rather than ignored. Because accepted parameters differ per model, a single shared UI showing identical controls will be lying somewhere.

Black Senpai

Defaulting to high is the expensive habit. Use it on the final image only.

How to build an estimate

  • Iterate at auto quality; raise quality only for the final image
  • Use the full per-run image cap — fewer runs means less cost and less waiting
  • Check each model's resolution floor and unsupported parameters; a rejected call is not a pricing problem
  • Keep video out of the same estimate — it is an order of magnitude apart

Frequently asked

Which image model is cheapest?
Of the three we measured, GPT Image 2 at about $0.019 per image. But quality=high takes it to $0.1299, so compare settings, not just models.
Should I turn quality up?
It costs about 6.8× and takes about 3× as long. Iterating at auto and using high only for the accepted image worked best.
What does video generation cost?
An order of magnitude more. Wan 3.0 measured $0.2125 for two seconds at 480p. Details are in our article on video cost.
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.