The cheapest image generation API is not the same model at every resolution. As of September 2026, GPT-Image-2 costs $0.0633 per image at 1K, 2K, or 4K, while Google models on the same key charge different prices by resolution tier. As a result, 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 list with one number per model hides this reversal. Decide the resolution you deliver before choosing a model.
Position first: Kunavo is its own product, a gateway that resells access to models, not an independent benchmark. The figures are taken from the catalog that bills the requests. Kunavo prices verified on October 1, 2026.
Price per image, by model and resolution
One price per image: the unit is the result, not the prompt. The “official price” is what the provider itself publishes for the same image (Google documentation, OpenAI pricing). A dash means the model does not offer 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 that charges by render speed, not resolution
Ideogram v3 has no resolution tiers: it charges by render speed, meaning the processing used for each image. The lower tier is for drafts, the higher one for the final asset. Do not compare these figures with the 1K/2K/4K columns above — they measure different things.
| 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: GPT-Image-2 costs about 2.5 times as much as the cheapest option.
- At 4K — GPT-Image-2 $0.0633, Nano Banana 2 $0.1057, Nano Banana Pro $0.1200: here GPT-Image-2 is the cheapest of the three.
A product that generates thumbnails benefits from Google models; one that delivers print-resolution artwork benefits from the flat price. To test with your monthly volume, use the AI image cost calculator and change the tier: you can see the model ranking change in front of you.
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 multiple source images per request, with the edit described in the prompt — this is what you use for compositing. Only the Ideogram v3 Edit accepts a mask: mark the area and only that area changes, which is the retouching workflow. Each edit counts as one image, so generating and editing twice costs three images per asset.
What Kunavo does not offer
These appear in lists in these search results and are not available on Kunavo as of September 2026: Flux, Seedream, Recraft, Stable Diffusion, Midjourney. If your work depends on one of them, this key will not work for that, and this is not the right key for you.
How to make a request
Generation and editing each have one endpoint, in OpenAI format; only the ID changes between models. Unlike video, images are returned in the same response, with no task to query later. The format is in the image documentation. The video side of the same key: video generation API; you can also pay with Pix.
Frequently asked questions
What is the cheapest image generation API?
It depends on the resolution you generate. As of September 2026, on Kunavo, Nano Banana 2 Lite is the cheapest at 1K, at $0.0255 per image, while GPT-Image-2 costs $0.0633. At 4K the order reverses: GPT-Image-2 remains at $0.0633, while Nano Banana 2 costs $0.1057 and Nano Banana Pro costs $0.1200. OpenAI does not charge extra for resolution, while Google does. Choose the resolution before the model.
Is there a free image generation API?
Not for production. Some providers offer trial credits and some apps have a free daily quota, but every image uses real-time GPU time, and no one offers an unlimited, free image API. The realistic floor is a few cents per image. If an API promises unlimited free images, first check what it resells and what it does with your prompts.
How much does it cost to generate an image via API?
On Kunavo, from $0.0255 to $0.1200 per image, depending on model and resolution. The unit is the generated image, not the prompt length, so a token calculator cannot estimate this cost. Failed generations are not charged, and the balance is prepaid with no monthly fee.
Does Kunavo have 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, and Ideogram v3) and 3 editing models. Flux, Seedream, Recraft, Stable Diffusion, Midjourney are not available with this key; if your work depends on one of them, another provider is the right answer.
Which model edits an existing image?
There are 3 editing models. Nano Banana Edit and GPT-Image-2 Edit accept multiple source images in one request, with the edit described in the prompt — useful for compositing a product into a scene. The Ideogram v3 Edit, starting at $0.02625 per image, is the only one on this key that accepts a mask: paint the area and only that area changes. Each edit is billed as one image.