The cheapest image generation API does not use the same model at every resolution. In September 2026, GPT-Image-2 costs $0.0633 per image at 1K, 2K, or 4K, while Google's models on the same key have resolution-tiered pricing. So GPT-Image-2 is the most expensive generation model at 1K and the cheapest at 4K—below Nano Banana 2 ($0.1057) and Nano Banana Pro ($0.1200). A tutorial focused on a single provider cannot show this. Set the delivery resolution before choosing a model.
First, a note on perspective: Kunavo is a product, a gateway that resells access to models, not an independent benchmark. The figures are taken from the catalog that charges for requests. Kunavo prices checked on October 1, 2026.
Price per image, by model and resolution
One price per image: the unit is the result, not the prompt. “Official price” is what the provider publishes for the same image (Google documentation, OpenAI pricing). A dash means the model does not have that resolution as a separate tier.
| Model | Provider | 1K | 2K | 4K | Official price (base) |
|---|---|---|---|---|---|
| Nano Banana 2 Lite | $0.0255 | — | — | $0.0340 | |
| Nano Banana | $0.0273 | — | — | $0.0390 | |
| Nano Banana 2 | $0.0469 | $0.0707 | $0.1057 | $0.0670 | |
| GPT-Image-2 | OpenAI | $0.0633 | $0.0633 | $0.0633 | $0.1266 |
| Nano Banana Pro | $0.0670 | — | $0.1200 | $0.1340 |
All prices in the table are below the provider's official price for the same image.
A model priced by speed, not resolution
Ideogram v3 has no resolution tiers: it charges by render speed, meaning the compute dedicated to each image. The cheaper tier is for drafts and the more expensive one for the final asset. These figures are not comparable to the 1K/2K/4K columns.
| Model | Render speed | Per image | Official price (base) |
|---|---|---|---|
| Ideogram v3 | Turbo | $0.02625 | $0.0300 |
| Ideogram v3 | Balanced | $0.0525 | $0.0600 |
| Ideogram v3 | Quality | $0.0750 | $0.0900 |
Where the ranking reverses
- At 1K — Nano Banana 2 Lite $0.0255, GPT-Image-2 $0.0633: about 2.5 times the cheapest option.
- At 4K — GPT-Image-2 $0.0633, Nano Banana 2 $0.1057, Nano Banana Pro $0.1200: GPT-Image-2 becomes the cheapest of the three.
Google models win by a wide margin for thumbnails; the flat price wins for print-resolution assets. The AI image cost calculator recalculates it using your monthly volume.
Editing an existing image
| Model | Per image | Multiple input images | Mask (inpainting) |
|---|---|---|---|
| Nano Banana Edit | $0.0273 | yes | no |
| GPT-Image-2 Edit | $0.0633 | yes | no |
| Ideogram v3 Edit | from $0.02625 (depending on speed) | no | yes |
Nano Banana Edit and GPT-Image-2 Edit accept several source images per request, with the edit described in the prompt—the compositing use case. Only Ideogram v3 Edit accepts a mask: you paint the area, and only that area changes. Each edit counts as one image, so generating and editing twice costs three images per asset.
What Kunavo does not have
These names recur on pages in this results set and are not on Kunavo as of September 2026: Flux, Seedream, Recraft, Stable Diffusion, Midjourney.
How to call it
Generation and editing each have an OpenAI-format endpoint; only the model ID changes. Unlike video, the image comes back in the same response, with no task to poll. The format is in the image documentation. The video side of the same key: video generation API.
Frequently asked questions
What is the cheapest image generation API?
It depends on the resolution you generate. In September 2026 on Kunavo, Nano Banana 2 Lite is the cheapest at 1K, at $0.0255 per image, and GPT-Image-2 costs $0.0633. At 4K the order reverses: GPT-Image-2 stays at $0.0633, while Nano Banana 2 rises to $0.1057 and Nano Banana Pro to $0.1200. OpenAI does not charge for resolution, while Google does. Choose the resolution before the model.
How much does an image generated through an API cost?
On Kunavo, from $0.0255 to $0.1200 per image, depending on the model and resolution. The unit is the generated image, not prompt length, so a token calculator cannot give you this cost. Failed generations are not charged, and the balance is prepaid with no subscription.
Is there a free image generation API?
Not for production. There are trial credits and apps with a free daily quota, but every image uses real GPU time: no one offers a free, unlimited image API. The realistic floor is a few cents per image.
Does Kunavo offer Flux, Seedream, Recraft, Stable Diffusion, Midjourney?
No. As of September 2026, Kunavo's image catalog has 6 generation models (Google Nano Banana, OpenAI GPT-Image-2, Ideogram v3) and 3 editing models. Flux, Seedream, Recraft, Stable Diffusion, Midjourney are not available with this key.
Which model edits an existing image?
There are 3 editing models. Nano Banana Edit and GPT-Image-2 Edit accept several source images per request, with the edit described in the prompt—useful for compositing a product into a scene. Ideogram v3 Edit, starting at $0.02625 per image, is the only one on this key that accepts a mask: only the painted area changes. Each edit is charged as one image.