GPT Image 2.6 vs Nano Banana 2.1 prompts: both guides write short, Nano Banana creators write six times longer
We compared OpenAI's GPT Image 2.6 guide, Google's Nano Banana guide and 155 creator prompts, and worked out the price per image from both vendors' own numbers. Both guides use short prompts, 71 and 40 words. Nano Banana 2.1 creators write a median of 250 words; GPT Image 2.6 creators write 100 for still images and one line for GIFs.
Summary
Pick between GPT Image 2.6 and Nano Banana 2.1 by the job, then write a short prompt for either one. Both vendors’ own examples are short; most of the length in creators’ prompts is optional.
The job decides the model because each one documents things the other does not:
- Only GPT Image 2.6 makes animated GIFs, edits from a circle you draw on the photo, exports SVG and has a complexity setting.
- Only Nano Banana 2.1 has the very tall and wide ratios 1:4, 4:1, 1:8 and 8:1; GPT Image 2.6 stops at 1:3 and 3:1. Google also states a limit of 14 reference images, with resemblance kept for up to 4 characters; OpenAI publishes no limit for 2.6.
The prompts are a different story. The reason to write short is simple: the vendors do. The median example in OpenAI’s prompting guide is 71 words in 4 lines; in Google’s guide it is 40 words in one line. Creators split:
- Nano Banana 2.1 creators write long. Their 88 prompts have a median of 250 words and 1,749 characters, six times Google’s examples.
- GPT Image 2.6 creators write short. Their 16 English still-image prompts have a median of 100 words. Their 31 GIF prompts have a median of 68 characters, one line.
On price, the two are close. At 1K, GPT Image 2.6 costs about $0.025 an image on low quality and $0.053 on high; Nano Banana 2.1 costs $0.0336. Near 4K, 2.6 on high comes to about $0.100 and Nano Banana $0.113.
Our picks
- Choose by feature first. GIFs, circled edits and SVG mean GPT Image 2.6. A 1:8 banner, a PDF as input, or many references with a stated limit for keeping characters consistent mean Nano Banana 2.1. For a plain still image, either works; try the same prompt on both.
- Start at the guide’s length. About 40 to 70 words: subject, setting, light, the words to render, the shape. Google’s product mockup example is one paragraph. Add detail only when the first image misses something.
- For GPT Image 2.6, say what the image is for and quote its words. Half of OpenAI’s examples name a use such as a poster, an ad or a diagram, and 27% put the exact text in quotes. A GIF can be one line:
大阪城を建築する流れをGIFにして(build Osaka Castle as a GIF) is a whole prompt. - For Nano Banana 2.1, name the ratio. 59% of 2.1 creator prompts do, and the extra tall and wide ratios only show up if you ask. For an edit, say what stays: the fisheye café selfie gives the face its own block.
- Price your real size and quality. GPT Image 2.6’s price moves with quality: the same 1024 square costs about twice as much on high as on low. Nano Banana’s moves only with size. If you render thousands of 1K images, low quality on 2.6 is the cheapest option here; at 2K the two are about even.
What are you making most often: a GIF or a marked-up edit, a very tall banner, or plain stills? The first two pick the model for you.
How we tested
- OpenAI’s examples. The 26 GPT Image 2.6 examples from OpenAI’s prompting guide in the open collection awesome-image-video-prompts at commit 590b532 (the live guide has 27; the collection skipped one duplicate).
- Google’s examples. The 14 example prompts in Google’s Nano Banana guide, read from the live page on November 7, 2026. We counted the Prompt tabs and left out the fill-in Templates.
- Creators. Every creator post on X for both models in the same collection: 67 for GPT Image 2.6 and 88 for Nano Banana 2.1. The 2.6 posts are from its first three days, November 4 to 6. The 2.1 posts run from October 5 to November 2, so we also checked the 23 posted in 2.1’s first three days.
- Features. For each prompt we counted characters, words and lines, and tested patterns: JSON, labeled sections, quoted text, an aspect ratio, camera terms, negative instructions (no, avoid, without), what must stay, and a named use such as poster or logo. The exact patterns are in the script.
- Price. For GPT Image 2.6 we used the output-token formula behind OpenAI’s own cost calculator at $30 per million image output tokens; at low quality and 1024 by 1024 it gives 823 tokens and $0.02469, the same as OpenAI’s page. Input tokens are extra. For Nano Banana 2.1 we used Google’s per-image prices.
Results
The vendors’ examples
| OpenAI, GPT Image 2.6 (26) | Google, Nano Banana (14) | |
|---|---|---|
| Median length | 71 words, 447 characters, 4 lines | 40 words, 229 characters, 1 line |
| Edits | 46% | 50% |
| Names what the image is for | 50% | 36% |
| Quotes the words to render | 27% | 14% |
| Negative instructions | 62% | 0% |
| Labeled sections | 19% | 0% |
Creators on X
| GPT Image 2.6, English stills (16) | GPT Image 2.6, GIFs (31) | Nano Banana 2.1 (88) | |
|---|---|---|---|
| Median length | 100 words, 728 characters | 68 characters | 250 words, 1,749 characters |
| Median lines | 2.5 | 1 | 5 |
| Aspect ratio named | 31% | 19% | 59% |
| Camera terms | 19% | 10% | 56% |
| Says what must stay | 31% | 29% | 51% |
| Negative instructions | 44% | 26% | 56% |
| Written as JSON | 0% | 0% | 12% |
Price per image, output only
| Size | GPT Image 2.6 low | medium | high | Nano Banana 2.1 |
|---|---|---|---|---|
| 1024 by 1024 (1K) | $0.0247 | $0.0435 | $0.0527 | $0.0336 |
| 2560 by 1440 (2K) | $0.0258 | $0.0473 | $0.0553 | $0.0504 |
| 3840 by 2160 (4K) | $0.0467 | $0.0856 | $0.1001 | $0.113 |
OpenAI calls sizes above 2560 by 1440 experimental, so the 4K row for GPT Image 2.6 is a beta size. Google’s 1K, 2K and 4K are its own size tiers.
Is the gap in creator prompts just the calendar? The 2.6 set is three days old, and launch posts tend to be quick tries. But Nano Banana 2.1’s own first three days give 23 prompts with a median of 1,461 characters, twice the 2.6 still prompts. The two communities write differently from day one.
One more contrast sits in the guides. 62% of OpenAI’s examples say what to leave out, such as no extra text or no watermark. None of Google’s 14 do. Google’s examples describe the image they want and stop there.
What to ignore
- Language. 41 of the 67 GPT Image 2.6 prompts are in Japanese or Chinese, because the collection searched in those languages for 2.6. All 88 Nano Banana 2.1 prompts are in English. Compare like with like: the English still images.
- Length as quality. We measured how people write, not which prompt gives a better image. The vendors’ short examples are the stronger evidence on what a model needs.
- Small price gaps. A few tenths of a cent per image disappears next to one retry. Price matters when you render at volume.
Limitations
- Small sets. 16 English still prompts for GPT Image 2.6 and 14 Google examples. One prompt moves a percentage by six or seven points.
- Different collection dates. The 2.6 creator set covers three days; the 2.1 set covers four weeks.
- We did not run the same prompt on both models. This says nothing about which image comes out better.
- GPT Image 2.6 prices are estimates from OpenAI’s formula and leave out input tokens, which grow with reference images.
- The features are text patterns, written mostly for English.
Reproduce it
The script is gpt-image-2-6-vs-nano-banana-2-1-prompts-2026-11.py. Clone the public collection, check out commit 590b532 and run the script on it; it needs Python and PyYAML and reads Google’s guide from the web. It writes gpt-image-2-6-vs-nano-banana-2-1-prompts-2026-11.json: one row per prompt with its features and a link to its source, every group summary and the price table. Prompt text is not copied into the data.