# GPT Image 2.5 Sunburst

OpenAI's most careful GPT Image 2.5 tier: slower, built for edits and detail that must survive a close look.

Last updated: 2026-10-05

**Key facts**

- GPT Image 2.5 Sunburst is the higher-effort tier of OpenAI's GPT Image 2.5, built for edits and fine detail that must survive a close look.
- GPT Image 2.5 Sunburst is Sloosh's default image model.
- GPT Image 2.5 Sunburst takes up to 16 reference images in Sloosh Studio, the most of any Sloosh image model, and prompts up to 32,000 characters.
- GPT Image 2.5 Sunburst offers six quality levels in Sloosh: Auto, low, medium, high, xhigh and max.

Web page: https://sloosh.ai/docs/gpt-image-2-5-sunburst

GPT Image 2.5 Sunburst is the higher-effort tier of OpenAI's GPT Image 2.5. It takes the same prompt and settings as Flare, but spends longer on each image, so fine detail, text and edits hold up better.

## When to use it

- Final assets where small text, labels and edges have to be right.
- Edits to a product photo where everything except one thing must stay the same.
- Pick [GPT Image 2.5 Flare](https://sloosh.ai/docs/gpt-image-2-5-flare.md) instead for quick drafts; it's up to 50% faster than GPT Image 2.

## How to prompt it

- Write in this order: the scene or background, the subject, the key details, then the constraints. Say what the image is for, such as a social ad or a banner.
- Put any words that must appear in quotes, and say where they go.
- Name references by number and job, for example "Image 1: product photo".
- For an edit, say "change only X", then list what must stay the same. Repeat that list every time you edit again.
- Quality goes up to max. Raise it only when you need to: compare medium and high first for small or dense text.

[Prompting GPT Image](https://sloosh.ai/docs/prompting-gpt-image.md) has the full guide for both 2.5 tiers and GPT-image-2.

## Example

A studio product photo goes in as Image 1; the prompt moves it onto wet slate and lists what must not change.

Input: product photo: ![An amber glass serum bottle with a black dropper and a cream label reading SERUM 01, on a light grey background](https://sloosh.ai/docs/in-bottle.webp)

->

Result: ![The amber SERUM 01 bottle standing on wet black slate with water droplets, lit from the upper right on a dark background](https://sloosh.ai/docs/m-gpt-image-2-5-sunburst.webp)

_1:1, quality high, Enhance off._

**Prompt**

```text
Image 1: a product photo of a serum bottle.
Place this exact bottle on a wet black slate surface scattered with a few water droplets. One soft light from the upper right, a dark charcoal background, crisp reflections on the glass. Square ad image for social media.
Keep the bottle's shape, the amber glass, the black dropper and the "SERUM 01" label exactly as they are. Change only the setting and the light.
```

## Settings in Sloosh

- Aspect ratio: Auto, 1:1, 3:2, 2:3, 16:9, 9:16, 4:5 or 5:4.
- Resolution: 1K, 2K or 4K.
- Quality: low, medium, high, xhigh or max.
- At 2K or 4K, an Auto aspect ratio renders square.
- References: up to 16 images.
- Prompt: up to 32,000 characters.

Open it in [Image](https://sloosh.ai/studio/image) and pick GPT Image 2.5 Sunburst in the model chip. The Generate button shows the cost first.

## Frequently asked questions

### What is GPT Image 2.5 Sunburst best for?

GPT Image 2.5 Sunburst is best for final assets where small text, labels and edges have to be right, and for edits where everything except one thing must stay the same. It spends longer on each image than GPT Image 2.5 Flare, so fine detail holds up better.

### GPT Image 2.5 Sunburst vs GPT Image 2.5 Flare: which should I use?

Use GPT Image 2.5 Flare for drafts and volume, and move to Sunburst when a detail won't hold. Both take the same prompts, up to 16 references and the same quality levels in Sloosh. OpenAI says Flare is up to 50% faster than GPT Image 2, while Sunburst spends longer per image.

### Which quality setting should I use with GPT Image 2.5 Sunburst?

Start on Auto and raise quality only when you need to. GPT Image 2.5 Sunburst offers Auto, low, medium, high, xhigh and max in Sloosh. OpenAI suggests comparing medium and high first when small or dense text won't come out right, since higher settings are slower.

### How do I edit a product photo with GPT Image 2.5 Sunburst?

Add the photo as Image 1, write "change only" the one thing, then list what must stay, such as the bottle shape, the glass and the label. GPT Image 2.5 Sunburst edits can drift over several rounds, so repeat the same keep list every time you edit again.

### Can GPT Image 2.5 Sunburst make a transparent background?

Not directly. Sloosh doesn't offer a transparent background setting on its GPT Image models. Generate the GPT Image 2.5 Sunburst image on a plain background, then open the result in Studio and use Remove BG in the edit toolbar.

## Sources

- [OpenAI image prompting guide](https://developers.openai.com/api/docs/guides/image-prompting)
- [OpenAI cookbook: image model prompting](https://developers.openai.com/cookbook/examples/multimodal/image-gen-models-prompting-guide)