# New image models: GPT Image 2.5, FLUX 3, Grok Imagine

> GPT Image 2.5 Sunburst, FLUX 3 and Grok Imagine Image 2 arrive on Tchavi: what each is for, sizes, prices in credits and KES, and a call you can copy.

- Published: 2026-10-18
- Author: Gael — Tchavi founder
- Canonical: https://tchavi.com/en/blog/new-image-models-gpt-image-2-5-flux-3-grok

---


Three image models arrive on Tchavi: GPT Image 2.5 Sunburst from OpenAI, FLUX 3 from Black Forest Labs and Grok Imagine Image 2 from xAI. The first is built for images with legible text, the second for photorealism and editing, the third for graphic styles at a single price.

## In short

- Tchavi, an OpenAI-compatible AI API gateway you pay for with mobile money, adds `gpt-image-2.5-sunburst`, `flux-3-image` and `grok-imagine-image-2`.
- All three generate and edit images from references.
- Prices run from 16 credits (about KES 1.2) to 667 credits (about KES 50) per image, depending on the model, quality and size.
- One endpoint for all of them: `POST /v1/images/generations`.

## GPT Image 2.5 Sunburst (OpenAI)

The precision tier of the GPT Image 2.5 range, released by OpenAI in September 2026. It renders legible text on the image, accents included: posters, flyers, menus.

- Three sizes: 1024×1024, 1024×1536 and 1536×1024, at the same price.
- Five qualities: `low`, `medium`, `high`, `xhigh`, `max`.
- Up to 16 reference images to edit or keep a style. Each reference adds 18 credits, because OpenAI bills input images.
- If you do not set `quality`, the request is billed at the `max` level. Always set the quality.

## FLUX 3 (Black Forest Labs)

The image model of Black Forest Labs' FLUX 3 family. Skin, fabric and light look like photographs.

- Four sizes: 1K, 1.5K, 2K and 4K, each at its own price. Every aspect ratio from 21:9 to 9:21.
- Up to 10 reference images to edit or combine.
- One image per request. 4K costs more than twelve times 1K: keep it for print.

## Grok Imagine Image 2 (xAI)

xAI's image model, released in August 2026. It handles strong graphic styles and short headlines well: posters, illustration, screen-print looks.

- Same price at 1K or 2K, at `low` or `medium` quality. If you set nothing, it produces at `medium` and 2K.
- Editing from a single reference image.
- One image per request.

## Prices

Credits first, then KES at October 2026 rates (1 credit is about KES 0.076):

| Model                  | Setting            | Credits per image | KES per image     |
| ---------------------- | ------------------ | ----------------- | ----------------- |
| GPT Image 2.5 Sunburst | low / medium       | 16 / 32           | 1.2 / 2.4         |
|                        | high / xhigh / max | 118 / 208 / 465   | 8.9 / 15.8 / 35.2 |
| FLUX 3                 | 1K / 1.5K / 2K     | 53 / 77 / 110     | 4.0 / 5.8 / 8.3   |
|                        | 4K                 | 667               | 50.5              |
| Grok Imagine Image 2   | 1K or 2K           | 88                | 6.7               |

A concrete example: a menu poster at `medium` on GPT Image 2.5 costs 32 credits, about KES 2.4. With three reference images, add 54 credits (about KES 4).

## One call to try it

```bash
curl -X POST https://tchavi.com/api/v1/images/generations \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $TCHAVI_API_KEY" \
  -d '{
    "model": "gpt-image-2.5-sunburst",
    "prompt": "Poster for a kitenge fabric shop in Nairobi, title \"End of month sale\", screen-print style",
    "quality": "medium",
    "size": "1024x1536"
  }'
```

The response contains the image as base64 in `data[0].b64_json`, and the cost in the `X-Credits-Used` header. For FLUX 3, change `model` to `flux-3-image` and send `resolution` (`"1K"`, `"2K"`…) instead of `quality`. For Grok, use `grok-imagine-image-2`.

## How to try them

- Open the model pages: [GPT Image 2.5 Sunburst](https://tchavi.com/en/m/openai/gpt-image-2.5-sunburst), [FLUX 3](https://tchavi.com/en/m/black-forest-labs/flux-3-image), [Grok Imagine Image 2](https://tchavi.com/en/m/xai/grok-imagine-image-2). Each shows a demo and the parameters in its API tab.
- Read the [image generation documentation](https://tchavi.com/en/docs/image-generation).
- Top up with mobile money from KES 250 (see [countries and operators](https://tchavi.com/en/docs/payments)): your credits do not expire.

## FAQ

### Which one for a poster with text?

Start with GPT Image 2.5 Sunburst at `medium`. Then compare with Grok Imagine for short headlines: same prompt, and look at the result.

### A host goes down: what happens?

For these three models, another host of the same model can take over. The advertised price does not change for you.

### Can I choose the FLUX 3 size?

Yes, from four fixed sizes: 1K, 1.5K, 2K and 4K. Set it with `resolution`, otherwise the default size is billed.

[create your account and top up KES 250](https://tchavi.com/en/register?next=%2Fdashboard%2Fbilling%3Famount%3D250%26currency%3DKES%26from%3Dblog-image-oct-en)

> _This article is part of the series "Building an AI product from Africa". Tchavi is an OpenAI-compatible AI API gateway: one key gives access to over 100 text, image, audio and video models, and you pay for it with mobile money, no bank card ([countries and operators](https://tchavi.com/en/docs/payments)). More guides on [the blog](https://tchavi.com/en/blog). Follow us: [LinkedIn](https://www.linkedin.com/company/tchavi) and [X](https://x.com/tchaviai)._