AI image generator comparison

ImageGPT v3 and Velvet Render v5.1 followed the prompts most accurately: in our test they spelled the requested text without errors and drew exactly three lemons in the bowl. Velvet Render v5.1 is also three times faster and accepts the daily bonus. OpenAI Image 2.5 and Nano Banana 2 handled every task too, but they often add lettering nobody asked for. Studio Vision v3 is the cheapest and fastest of the six but miscounts objects, and Studio Vision v3.6 garbles text more often than the others.

Run on October 15, 2026. We compared the six most popular AI image generator models in Problembo on five identical prompts.

Summary

* The task was done, but the model added lettering and slogans that were not in the prompt.

How we tested

• Models. The six image generator models with the most tasks from Problembo users over the last 30 days. Deprecated models were excluded.
• Prompts. Five English prompts for typical tasks: a portrait, a product photo, text in the frame, an illustration, and a scene with several objects in exact positions. Every model received each prompt unchanged, without a negative prompt, one image per run.
• Settings. Default settings, 1K resolution where it can be selected. The exception is ImageGPT v3, run at High quality, which most of its tasks use. The aspect ratio was the same for every model within a prompt, but the exact frame size differs between models.
• Time. The median of all successful single-image tasks with the same settings in Problembo over the last 30 days, from submission to result. In our run, one task took 16–24 s with Velvet Render v5.1, 51–106 s with ImageGPT v3, 27–44 s with OpenAI Image 2.5, 23–24 s with Nano Banana 2, 27–41 s with Studio Vision v3.6, and 12–20 s with Studio Vision v3, including queue time.
• Test cost. 30 generations cost $1.47.

Results by prompt

Photorealistic portrait

Close-up portrait photo of a 35-year-old woman with freckles and curly red hair, wearing a knitted green sweater, soft window light, natural skin texture, shallow depth of field, 85mm lens

Velvet Render v5.1

ImageGPT v3

OpenAI Image 2.5

Studio Vision v3.6

Studio Vision v3

Nano Banana 2

All six models handled the portrait: red curls, freckles, and the green sweater are everywhere. Studio Vision v3 and Velvet Render v5.1 give the most natural skin. OpenAI Image 2.5 and Nano Banana 2 shoot in a stock-photo style with a smile, an interior, and neat lighting. ImageGPT v3 and Studio Vision v3.6 place the woman strictly face-on, which looks like an ID photo.

Product photo

Product photo of a matte black ceramic coffee mug with steam rising from it, standing on a light oak table next to scattered coffee beans, soft studio lighting, clean white background, commercial catalog style

Velvet Render v5.1

ImageGPT v3

OpenAI Image 2.5

Studio Vision v3.6

Studio Vision v3

Nano Banana 2

OpenAI Image 2.5, Studio Vision v3, and Velvet Render v5.1 did the catalog shot best: a matte mug, steam, coffee beans, and a light background. ImageGPT v3 made a clean frame but forgot the steam. Nano Banana 2 put a logo on the mug and added a spoon, while Studio Vision v3.6 wrote meaningless ad copy in the background, so the shot is unusable for a catalog.

Text in the image

Photo of a cozy coffee shop storefront in daylight. Above the door is a large wooden sign that reads "MORNING BREW". Next to the door stands a chalkboard with the handwritten text "Fresh croissants 9 AM"

Velvet Render v5.1

ImageGPT v3

OpenAI Image 2.5

Studio Vision v3.6

Studio Vision v3

Nano Banana 2

Every model spelled the "MORNING BREW" sign correctly. ImageGPT v3, OpenAI Image 2.5, Velvet Render v5.1, and Studio Vision v3 reproduced the chalkboard text exactly. Nano Banana 2 added "& pastries" and "Daily specials" to the board, and Studio Vision v3.6 repeated "AM" twice and put unreadable lettering on the door. OpenAI Image 2.5 decorated the windows with slogans of its own.

Watercolor illustration

Watercolor children's book illustration of a fox and a rabbit having a picnic under a big oak tree, a red checkered blanket, a basket of apples, warm autumn colors, soft paper texture

Velvet Render v5.1

ImageGPT v3

OpenAI Image 2.5

Studio Vision v3.6

Studio Vision v3

Nano Banana 2

The fox, the rabbit, the checkered blanket, and the basket of apples are in every image. Nano Banana 2 comes closest to a picture-book watercolor with paper texture, uneven edges, and a warm palette. ImageGPT v3 and Nano Banana 2 dressed the animals, and OpenAI Image 2.5 again added lettering on the tree. Velvet Render v5.1 drew the simplest scene, but with a visible watercolor texture.

Complex scene with several objects

Photorealistic kitchen table by a rainy window. On the left, a red teapot. In the center, a blue bowl with exactly three yellow lemons. On the right, a black cat sitting on a stack of two books. A green plant on the windowsill

Velvet Render v5.1

ImageGPT v3

OpenAI Image 2.5

Studio Vision v3.6

Studio Vision v3

Nano Banana 2

This prompt checks whether a model keeps count, colors, and positions: a red teapot on the left, a blue bowl with exactly three lemons in the center, and a black cat on two books on the right. ImageGPT v3, OpenAI Image 2.5, Nano Banana 2, and Velvet Render v5.1 got everything right. Both Studio Vision models put four lemons in the bowl. OpenAI Image 2.5 and Nano Banana 2 added titles to the book spines without being asked.

Which model to choose

• Velvet Render v5.1 is the default choice for photos: it follows the prompt closely, handles short text, and costs $0.05. You can pay for it with the daily bonus.
• ImageGPT v3 when exact text and layout matter more than speed: one High-quality image takes about a minute.
• OpenAI Image 2.5 for rich scenes and illustrations. If extra lettering gets in the way, forbid it in the prompt, for example no text, no signs.
• Nano Banana 2 for lively photos and stylized illustrations. It offers up to 4K resolution.
• Studio Vision v3 for fast, cheap photorealistic drafts, including image-to-image. Check object counts.
• Studio Vision v3.6 for portraits and scenes without text.

OpenAI Image 2.5, Nano Banana 2, and ImageGPT v3 accept only paid balance and may reject a prompt if moderation considers it unsafe. For drawn characters, see the anime model comparison.

Test limitations

Each prompt was run once, and another run will produce a different image. The prompts were in English. Midjourney 8.2, Velvet Render v4, PhotoStab v3 Ultra, PhotoStab v2.5, and deprecated models were not included; their prices and use cases are on the service page. We will update the comparison when new models arrive.