GPT Image 2 vs Nano Banana API: Pricing, Benchmarks, and Which to Use

GPT Image 2 and Nano Banana are the two image APIs most teams shortlist in 2026: OpenAI's April 2026 flagship against Google's Gemini image family. Both generate and edit images from the same kind of prompt-plus-references request, both run on Unifically through one endpoint and one API key, and their per-image prices overlap almost exactly. The differences that should drive the choice are benchmark position, aspect-ratio range, reference limits, and where each one is cheapest. This post compares all four, with live Arena numbers and a working request for each model.

TL;DR: GPT Image 2 (openai/gpt-image-2) is #1 on both Arena image boards as of August 18, 2026 (text-to-image Elo 1381, image edit Elo 1463), at $0.03 / $0.05 / $0.08 per image for 1K / 2K / 4K. Nano Banana 2 (google/nano-banana-2) ranks #7 in text-to-image and #10 in edit at $0.034 / $0.051 / $0.076, and answers with ten aspect ratios (vs four) and 20 reference images (vs 16). For volume drafts, Nano Banana 2 Lite is the cheapest of the set at $0.02 per image.

Which Nano Banana are we talking about?

"Nano Banana" is the nickname for Google's Gemini image models, and in 2026 it is a family:

• Nano Banana 2: the current Flash-class model and the default comparison target. Resolution-priced at 1k, 2k, or 4k.
• Nano Banana 2 Lite: the volume variant at a flat $0.02 per image.
• Nano Banana Pro: Gemini 3 Pro Image, with reasoning over references and the strongest text rendering in the family.
• Nano Banana (original, Gemini 2.5 Flash Image): superseded. It now sits at #30 in text-to-image on Arena, well behind its successors.

Unless you have a reason to pick otherwise, "GPT Image 2 vs Nano Banana" in 2026 means GPT Image 2 vs Nano Banana 2, with Pro as the family's quality play. That is how this post compares them.

Specs side by side

The spec table is where Nano Banana wins. Ten aspect ratios cover 21:9 banners, portrait posters, and social formats that GPT Image 2's four ratios cannot produce without cropping. Twenty references beat sixteen, though GPT Image 2 accepts much larger files per reference (100 MB vs 10 MB). If your pipeline needs an exact ratio or a big reference stack, that decides it before any benchmark does.

Arena benchmarks (August 2026)

Live positions on Arena's community-voted boards, pulled August 18, 2026:

Text-to-image:

Image edit:

The current picture is one-sided at the top: GPT Image 2 holds #1 on both boards, 117 Elo ahead of Nano Banana 2 in text-to-image and 74 ahead of Nano Banana Pro in edit. The Nano Banana family still places three models in each top 16, and the gap between Nano Banana 2 and Pro is small enough that the cheaper model is usually the right one of the two. Boards move, but both models are heavily voted (70k+ votes on GPT Image 2's text-to-image row, 500k+ on Pro's edit rows), so these are stable ranks. Still, check the date on any comparison you read.

Pricing per image

Verified against the live API on August 18, 2026:

Read it by budget, not by brand. At 1K, GPT Image 2 is slightly cheaper and better ranked, so drafts default there. At 4K, Nano Banana 2 undercuts by less than half a cent. The real price lever is Nano Banana 2 Lite at $0.02: for high-volume pipelines where each image is a draft, it costs a third less than anything else in this post. Billing on Unifically is pay-per-use with no subscription, and a new account's $0.20 free balance covers a first test batch: six GPT Image 2 images at 1K, or ten on Nano Banana 2 Lite.

How to call both APIs

Both models run through the same async task endpoint with one API key. GPT Image 2:

curl -X POST https://api.unifically.com/v1/tasks \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "model": "openai/gpt-image-2",
    "input": {
      "prompt": "Product hero shot of a matte black espresso machine, studio lighting",
      "resolution": "1K",
      "aspect_ratio": "3:2"
    }
  }'

Nano Banana 2 takes the same shape with its own ratio and resolution values:

curl -X POST https://api.unifically.com/v1/tasks \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "model": "google/nano-banana-2",
    "input": {
      "prompt": "Product hero shot of a matte black espresso machine, studio lighting",
      "resolution": "1k",
      "aspect_ratio": "21:9"
    }
  }'

Each call returns a task_id; poll GET /v1/tasks/<task_id> or set a callback_url. Add image_urls to either request for reference-guided generation or editing. Full parameter docs: GPT Image 2 pricing and limits and Nano Banana 2 pricing and variants.

Which should you use?

Default to GPT Image 2 when output quality is the point: it leads both Arena boards, its 1K rate is the cheapest non-Lite option, and its resolution-priced variants make draft-to-final budgeting predictable. It is also the stronger pick for edits today, by a clear margin on the edit board.

Pick Nano Banana 2 when format flexibility matters more than a benchmark lead: ten aspect ratios against four is the practical difference teams feel first, especially for 21:9 banners and portrait social work. It is also the pick when you need more than 16 references, or SynthID provenance marks in the output.

Pick Nano Banana 2 Lite for volume. At $0.02 per image, brute-force iteration is affordable in a way neither flagship matches: sweep prompts on Lite, then re-run the survivors on GPT Image 2 or Nano Banana Pro.

Both are live on Unifically behind one key, so the honest answer for most teams is both: quality passes on one, format or volume work on the other, with no separate accounts to maintain. Try them in the playground with the free signup balance.

Frequently asked questions

Is GPT Image 2 better than Nano Banana?

On community benchmarks, yes, right now: GPT Image 2 ranks #1 in both text-to-image (Elo 1381) and image edit (Elo 1463) on Arena as of August 18, 2026, ahead of Nano Banana 2 at #7 and #10. Nano Banana still wins on aspect-ratio range, reference count, and volume price.

Is Nano Banana cheaper than GPT Image 2?

At 1K, no: GPT Image 2 costs $0.03 against Nano Banana 2's $0.034. At 4K, Nano Banana 2 is slightly cheaper ($0.076 vs $0.08). The cheapest option overall is Nano Banana 2 Lite at a flat $0.02 per image.

What is Nano Banana 2?

Nano Banana 2 is the current Flash-class model in Google's Gemini image family (gemini-3.1-flash-image on Arena's boards), served on Unifically as google/nano-banana-2. You pick 1k, 2k, or 4k at request time and pay the matching per-image rate.

Can I try GPT Image 2 and Nano Banana free?

Yes. New Unifically accounts start with $0.20 of free balance, which covers six GPT Image 2 images at 1K or ten Nano Banana 2 Lite images, in the browser playground or through the API. After that, billing is pay-per-use with no subscription.

We will update this post when either model's pricing changes, when Arena ranks shift meaningfully, and when OpenAI or Google replaces these models with successors.