Nano Banana 2.1 vs GPT Image 2: Two Matched-Prompt Tests

Nano Banana 2.1 and GPT Image 2 can both produce polished images from structured prompts, but the useful question is not which model is “best” in the abstract. It is how each behaves on the exact constraints your workflow cares about.

We ran two matched-prompt tests in WeShop: a text-heavy four-step infographic and a photorealistic snow-globe scene with strict object counts and composition rules. Each prompt was run once per model, so this is a small practical comparison—not a benchmark. The WeShop GPT Image page is currently titled “GPT Image 2.5,” but the returned task metadata for these runs identified the actual model as gpt-image-2. This article therefore reports the executed model as GPT Image 2.

How we kept the comparison fair

Both models received the same wording for each test. We judged only visible outputs and task metadata: literal text, counts, spatial placement, exclusions, aspect-ratio adherence, and finish. We did not compare speed or price because the web interfaces and settings were not equivalent enough for a controlled claim.

The Nano Banana runs used the visible Nano Banana 2.1 selector. The GPT runs used the WeShop GPT Image page; its result metadata labeled the model gpt-image-2. The GPT interface did not expose the same aspect-ratio and resolution controls as the Nano Banana interface during this test.

Test 1: exact-text process infographic

The prompt requested a 4:5 infographic titled “FROM RAIN TO TAP,” four numbered vertical panels, four exact step titles, four exact captions, clear downward arrows, and no extra words.

Create a finished 4:5 educational process infographic titled exactly “FROM RAIN TO TAP”. Use four equal numbered panels stacked vertically with one clear downward arrow between panels.
Panel 1 title exactly “COLLECT” with a rain cloud feeding a reservoir and caption exactly “Rain fills the reservoir.” Panel 2 title exactly “FILTER” with gravel, sand, and charcoal layers and caption exactly “Layers remove particles.” Panel 3 title exactly “DISINFECT” with a blue UV light chamber and caption exactly “UV light reduces microbes.” Panel 4 title exactly “STORE” with a covered water tank and caption exactly “Clean water waits safely.”
Use flat vector illustration, navy outlines, pale blue and teal fills, warm ivory background, generous margins, consistent icons, high text contrast, and a single reading path from top to bottom. No other words, no decorative labels, no side panels, no logo, no watermark.

NANO BANANA 2.1

GPT IMAGE 2

Both models passed the content test. Nano Banana 2.1 followed the requested ratio and produced a taller, more spacious layout. GPT Image 2 made a clean and highly legible card-like design, but the returned ratio differed from the prompt.

Test 2: photorealism with exact object constraints

The second prompt asked for exactly one snow globe containing one Victorian greenhouse, exactly three red orchids, and one brass telescope. It also specified one lightning bolt in the upper-left, one candle on the right, mixed cool and warm lighting, and a fully visible globe.

Create a finished 3:4 photorealistic editorial image of exactly one clear glass snow globe resting on a dark walnut desk during a thunderstorm. Inside the globe is one miniature Victorian greenhouse containing exactly three red orchids and one small brass telescope. Place a sharp lightning bolt in the upper-left background and one lit ivory candle on the desk to the right of the globe. Use realistic glass reflections and refractions, cool blue storm light from the left, warm candlelight from the right, shallow depth of field, and detailed natural materials. Keep the entire globe visible. No people, no extra flowers, no extra globes, no text, no logo, no watermark.

NANO BANANA 2.1

GPT IMAGE 2

GPT Image 2 created more elaborate greenhouse architecture, luminous glass, and a refined tabletop scene. Nano Banana 2.1 delivered the requested portrait framing with a simpler but coherent miniature. Both counted the three orchids correctly.

Side-by-side results

Which model should you choose?

Choose Nano Banana 2.1 when explicit canvas control and a structured visual brief are central to the workflow, especially if you want visible ratio and resolution controls in the tested WeShop interface.

Choose GPT Image 2 when photorealistic finish and rich material rendering are the priority and you can crop or adapt the returned canvas afterward. In our two runs, its content adherence was strong even when its output ratio differed.

Do not select a production model from two examples alone. Test both on your own hardest prompts, run several repetitions, and score the requirements that matter to you: text, identity, product fidelity, ratio, latency, and revision cost.

Final verdict

This small test produced no universal winner. Nano Banana 2.1 was more faithful to the requested orientation. GPT Image 2 delivered a more elaborate photorealistic result, while matching the hard content constraints. Both generated an accurate infographic in one run.

For a deeper look at Nano Banana’s behavior, read our Nano Banana 2.1 Review. For prompt structure, see the Nano Banana 2.1 Prompt Guide.