Comparison · Images
Nano Banana 2 vs GPT Image 2.5
Nano Banana 2 vs GPT Image 2.5: four images per call, 8:1 banners and 4K, or one flat price per image in three sizes. Quality is close, so cost decides.
What each one accepts
| Nano Banana 2 | GPT Image 2.5 | |
|---|---|---|
| Vendor | OpenAI | |
| Type | Image | Image |
| Modes | text-to-image image-to-image | text-to-image image-to-image |
| Released | 2026-02 | 2026-09 |
| Resolutions | 0.5K, 1K, 2K, 4K | - |
| Aspect ratios | 1:1, 2:3, 3:2, 3:4, 4:3, 4:5, 5:4, 9:16, 16:9, 21:9, 1:4, 4:1, 1:8, 8:1 | auto, 1024x1024, 1536x1024, 1024x1536 |
| Reference images | up to 14 | up to 16 |
| Prompt length | up to 32,000 chars | up to 32,000 chars |
| Quality | - | auto, low, medium, high, xhigh, max |
Rates and clip costs
| Model | Variant | Rate |
|---|---|---|
| Nano Banana 2 | 0.5K | $0.07 / image |
| 1K | $0.07 / image | |
| 2K | $0.0875 / image | |
| 4K | $0.113 / image | |
| GPT Image 2.5 | - | $0.05 / image |
Charged from a prepaid USD balance, no taxes added. A failed generation is $0.
On quality these two are neck and neck in my tests, and both get text in images right. So the choice is practical. Nano Banana 2 gives you up to four variants per call, extreme formats and the shorter wait. GPT Image 2.5 charges one flat price per image, which makes it the cheaper tool for ongoing graphics when its three sizes are enough.
When to pick Nano Banana 2
- You want four thumbnail options for an A/B test from a single request.
- The layout is a long 8:1 banner or a narrow 1:8 strip.
- You need 2K or 4K, which GPT Image 2.5 does not offer.
- Waiting time matters: it averaged 12.2 s per image in my runs.
When to pick GPT Image 2.5
- You produce a steady series of blog or social graphics and watch the cost per image.
- You want the same price at
low,highandmaxquality. - A 1024x1024 square, 1536x1024 landscape or 1024x1536 portrait covers your needs.
- The project uses 15 or 16 references.
Differences you will notice
- Price. GPT Image 2.5 costs $0.05 per image for any size or quality. Nano Banana 2 costs from $0.07 per image at 1K, about 1.6x more, and the rate climbs at 2K and 4K. Its 0.5K tier is billed like 1K.
- Variants. Nano Banana 2 returns up to 4 images (
num_images), each billed. GPT Image 2.5 returns one per request. - Formats. Nano Banana 2 has tiers from 0.5K to 4K and 14 ratios including 1:8 and 8:1. GPT Image 2.5 has three fixed sizes or
auto; custom sizes are not available in Kadraris yet. - References. 14 for Nano Banana 2, 16 for GPT Image 2.5.
- Wait. Measured through another API: GPT Image 2.5 took about 18 s at
highand 38 s atmax, against 12.2 s for Nano Banana 2.
How to decide
- Need several options at once, a 4K file or an odd format: Nano Banana 2.
- Need many single graphics at a predictable price: GPT Image 2.5.
In my scoring Nano Banana 2 got 8.6/10 and GPT Image 2.5 got 8.5 at high and 8.6 at max on the same prompts. Both wrote an accented Polish sign without mistakes, and Nano Banana 2 also cleared a harder pangram test. Its quirks: it sometimes adds elements nobody asked for, and it once turned pierogi into something closer to gyoza. For 4K from OpenAI there is GPT Image 2. A three-way look with FLUX.2 is in GPT Image 2.5 vs Nano Banana Pro vs FLUX.2, and rates on /pricing.
Questions
How do I get four variants out of GPT Image 2.5?
Send four separate requests. Each is one image at the flat rate. Nano Banana 2 does it in one call with num_images: 4, but you still pay for four images.
Which is safer for a poster with lots of text?
Both handled accented text well. Nano Banana 2 passed the tougher pangram check too, but proofread every line whichever you choose.
Does a higher quality setting raise the GPT Image 2.5 price?
No. max costs the same as low; it only takes longer to render.
Samples from the makers
Nano Banana 2
GPT Image 2.5
These clips and images come from the vendors, not from my runs.