GPT Image 2.5 vs Flux 2 Pro: The New One and the Workhorse
Flux 2 Pro takes JSON prompts and hex colours, and charges by the megapixel. GPT Image 2.5 is ten months newer, takes twice as many references, and accepts a mask.
GPT Image 2.5
OpenAI's newest image model comes in a fast variant and a quality variant. Both do 4K and both edit an existing image without wrecking the rest of it.
- Made by
- OpenAI
- Good for
- Editing one part of a picture and leaving everything else alone
- Weak at
- Very wide or very tall crops, because the shape limit stops at 3:1
- Resolution
- 1K, 2K or 4K
Flux 2 Pro
Black Forest Labs' production image model takes a structured prompt instead of a paragraph, matches an exact hex colour, and charges a published rate per megapixel.
- Made by
- Black Forest Labs
- Good for
- Jobs where a program writes the prompt, not a person
- Weak at
- Using all eight references at a large output size, because of the shared budget
- Resolution
- 64x64 up to 4 megapixels, every edge a multiple of 16
Round by round
| Criterion | Winner | Why |
|---|---|---|
| How new it is | GPT Image 2.5 | Released 8 September 2026. Flux 2 shipped 25 November 2025 and its maker has since moved on to a newer family. |
| Reference images | GPT Image 2.5 | Up to 16 on the edits endpoint. Flux 2 Pro takes 8 through the API, 10 in Black Forest Labs' own playground. |
| Masked editing | GPT Image 2.5 | It accepts a PNG mask with an alpha channel. Flux 2 Pro edits from references and instructions. |
| Prompting in JSON | Flux 2 Pro | Structured JSON prompts and hex colour codes are documented features. OpenAI documents labelled plain text. |
| Knowing the price before you generate | Flux 2 Pro | $0.03 for the first output megapixel, $0.015 for each one after. OpenAI charges by token, which is harder to predict. |
| Top resolution | GPT Image 2.5 | Up to 3840x2160. Flux 2 Pro is documented at up to 4 megapixels. |
| Quality settings | GPT Image 2.5 | Six levels from low to max. Flux 2 Pro hides sampling controls by design. |
| Running it yourself | Flux 2 Pro | Pro is closed, but the same family has an open-weight sibling. OpenAI publishes no weights at all. |
These two models land in the same place from opposite directions. Both make sharp images with readable text. Both edit an existing picture from references. Both are aimed at people producing work, not people exploring.
The difference is in how you talk to them and how you pay. Flux 2 Pro accepts a structured JSON prompt with hex colour codes, and charges a published price per megapixel. GPT Image 2.5 wants labelled plain text, charges by token, and is ten months younger.
The short version
There is a timing point that matters more than any spec. Flux 2 shipped in November 2025. Black Forest Labs has since released a newer family and now describes Flux 2 as supported rather than current. GPT Image 2.5 is the newest model either company has shipped in this comparison. That does not make it better output. It does mean one of the two is still being pushed forward.
Everything here comes from published documentation. I have not run production work through either model.
Side by side
| GPT Image 2.5 | Flux 2 Pro | |
|---|---|---|
| Maker | OpenAI | Black Forest Labs |
| Released | 8 September 2026 | 25 November 2025 |
| Variants | Flare and Sunburst | pro, flex, dev, klein, max |
| Max output | 3840x2160, 8.29 million pixels | Up to 4 megapixels |
| Sizes | Any, if both edges divide by 16 and the ratio stays inside 1:3 to 3:1 | Any width and height from 64 up, plus preset ratios |
| Preset ratios | 1024x1024, 1536x1024, 1024x1536 and more | 1:1, 16:9, 9:16, 4:3, 3:2, 21:9 |
| Text in image | Documented as improved, with a caution about placement | Documented for typography, infographics and UI mockups |
| Editing | Yes, including a mask with an alpha channel | Yes, from multiple references, in the same model |
| Reference images | Up to 16 on the edits endpoint | 8 through the API, 10 in the playground |
| Reference budget | Not published as a shared budget | Inputs and output share 9 megapixels, so more pixels means fewer references |
| Structured prompts | Labelled plain text | JSON, plus hex colour codes |
| Quality settings | low, medium, high, xhigh, max, auto | None exposed on pro |
| Output formats | PNG, JPEG, WebP | JPEG, PNG, WebP |
| Transparent background | Yes | Not documented |
| Price | $8 per million tokens in, $30 per million out | $0.03 for the first output megapixel, $0.015 each after |
One number on that table is widely repeated wrong. Flux 2 Pro’s reference limit is 8 through the API. The “10 references” figure you will see everywhere is the playground limit, and it also applies to a different variant. The API schema has eight slots and no more.
The shared megapixel budget is the part people trip over. Inputs and output come out of the same 9 megapixels. So eight references is realistic at a small output and impossible at a large one.
How you write for each one
GPT Image 2.5 wants a small form, not a paragraph. Scene, subject, details, style, constraints, each on its own line. Literal words go in quotes. For an edit, name what changes, what stays and what is banned, and repeat the “stays” list every round.
Flux 2 Pro takes the same information and lets you send it as structure. You can hand it JSON instead of prose, and you can name a colour as a hex code rather than describing it. That removes the guessing from brand work. “Deep navy” is an opinion. A hex value is not.
Escape angle brackets if you are pasting from a web page like this one. In the tool itself you type them normally.
| Task | GPT Image 2.5 | Flux 2 Pro |
|---|---|---|
| Exact brand colour | Describe it, then check the result | Give the hex code |
| Change one region | Attach a mask | Attach the reference and describe the change |
| A hundred product cards | Script the labelled text | Send JSON, price it per megapixel |
| Layered design file | Ask for a transparent background | Not documented |
Where to run each one
OpenArt names GPT Image 2.5, in Flare and Sunburst. It does not name Flux 2 Pro.
ImagineArt names Flux 2 Pro. It lists GPT Image 2 rather than 2.5, so it is not a route to the newer OpenAI model.
Creatify is the only platform of the five that names both, and both sit on its Pro plan. Vosu names Flux without a version, so you cannot tell from the pricing page which one you get. Figma Weave lists Flux 2 Pro and a faster Flux variant, plus GPT Image 1.5 rather than 2.5.
So there is no cheap single account that gives you both. If you only need one, pick the platform for the model, not the other way round.
What this comparison does not cover
I have not generated with either model. Nothing here is a judgement on output quality, and this page cannot tell you which one draws a better hand or a cleaner logo.
It cannot compare text rendering fairly. Black Forest Labs claims legible fine text and UI mockups. OpenAI says its text is significantly improved and then warns in the same guide that placement and clarity can still fail. A claim and a caution are not comparable.
I could not verify a prompt length limit for Flux 2 Pro. A 32,000 token figure appears on one Black Forest Labs page and nowhere else, so it is left out.
I could not verify which image file types Flux 2 Pro accepts as input. Its docs describe how you send an image, by URL or base64, but never list the formats.
I could not compare real cost on the platforms above. None of them publishes the credit cost of one generation with either model, so the maker’s prices are the only honest figures on this page.
Questions
Is Flux 2 Pro out of date?
It is not retired. Black Forest Labs still supports it, and it is on four of the five platforms here. It is no longer the company’s newest family, so expect improvements to land elsewhere.
How many reference images can Flux 2 Pro really take?
Eight through the API. Ten if you use Black Forest Labs’ own playground, and ten on a different, more expensive variant. Fewer than eight in practice when your output is large, because inputs and output share one pixel budget.
Which is cheaper for one image?
Flux 2 Pro is the only one of the two with a price you can work out in advance. A one megapixel image is $0.03, and an edit with references starts around $0.045. OpenAI charges by token, so the answer depends on your size and quality settings.
Can I run either one on my own machine?
Not these two. Flux 2 Pro is closed, though the same family includes an open-weight version under a non-commercial licence. OpenAI publishes no weights.
Which one for text on packaging?
Both are built for typography. Flux 2 Pro gives you hex colours, which helps when the brand palette is fixed. GPT Image 2.5 gives you a mask, which helps when only the label has to change and the bottle must not.