AI Image Editing Tool Comparison! Which is the Most Realistic Image Generator through Testing the Latest Models: Google, OpenAI, and ByteDance? [Fall 2025]

Introduction

On Friday, October 24, 2025, I participated as a presenter at CO-LAB Tech Night vol.4 held at our Osaka Tech Lab. At this event, I presented on the topic of testing the consistency of gpt-image-1, Gemini 2.5 Flash Image, and Seedream 4.0. Since Google recently released Nano Banana pro, I have updated some of the content and would like to share it here as well.

The content involves using image generation and editing features provided by OpenAI, Google, and ByteDance to perform image editing on the same tasks and examine what kind of output results we get. If you are wondering which tool is the most suitable for you, I hope this will be helpful.

What is gpt-image-1?
The model is released in March 2025 and integrated as standard in GPT-4o with a feature capable of image generation and editing. In APIs and other contexts, it is sometimes called by its model name gpt-image-1.
A parameter called input_fidelity is enabled. Setting the parameter to high helps significantly improve the consistency of subjects and characters in image editing, which gathered attention. The model has no reference feature but inpainting feature.

What is Gemini 3 Pro Image?
Commonly known as Nano Banana, it is said to be tuned specifically to maintain consistency of subjects and characters. At its launch, the model with high performance become a hot topic on social media. Upgraded to 3 Pro, the model’s text generation feature is apparently enhanced. Nano Banana was released in August 2025 with reference feature support but without inpainting.

What is Seedream 4.0?
The model includes a feature to output massive 4K images with fast speed, as well as a capability of handling professional commercial workflows. Particularly, the model’s high subject and character consistency also became a topic on social media. The model was released in September 2025 with both reference and inpainting feature support.

AI's Weakness: Maintaining the Subject and Character Consistency
When you want to edit only part of an image, AI models often regenerate the entire image, which makes it difficult to maintain the image consistency. Iterated generation by AI models causes gradual changes in the original image; however, such weakness is currently being overcome.

So, I would like to compare and examine the output images from these three tools.
By the way, for Gemini 3 Pro Image and Seedream 4.0, I used the reference feature (a function that modifies the original image by referencing another image). On the other hand, for gpt-image-1, which does not have a reference feature, I performed editing by overlaying subjects onto the original image. Therefore, while I tried to keep the prompts for all the tools as similar as possible, I applied the ones with slightly different content for gpt-image-1.
In this comparison experiment, I generated an average of around 10 images and am posting the output that showed the best results among them.

Task 01: Writing Texts on a Blank Label

The task is to write a product name on a blank label on a bottle in the following image.

Comparison of Output Results

gpt-image-1

The text is somewhat distorted, but no major breakdown was observed. Overall consistency is maintained.

Gemini 3 Pro Image

The thickness and size of the text are fine, and no particular breakdown was observed. Overall consistency is maintained.

Seedream4.0

The thickness and size of the text are fine, and no particular breakdown was observed. Overall consistency is maintained.

Task 02: Change to a Top-Down Angle

The task is to change an image of sunflowers in a vase photographed from the side to a top-down angle.

Comparison of Output Results

gpt-image-1

The angle is from directly above the sunflowers. Their petals somehow feel artificial.

Gemini 3 Pro Image

The angle is from directly above the sunflowers, but they may look slightly small. The texture of the petals looks realistic.

Seedream4.0

The image is ended up being slightly from above at an angle, but the texture of the flowers and the detail where just a sunflower on the right side has changed direction have been reproduced.

Task 03: Seat a Family in the Back Seat of a Vehicle

The task is to edit the people in a family photo as if they are seated in the back seat of a vehicle.

Comparison of Output Results

gpt-image-1

Facial consistency does not appear to be maintained. And the overall color of the image appeared somewhat yellowish. However, the balance between the people and seat sizes seems good.

Gemini 3 Pro Image

The balance, color tone, and other aspects appear to be output with quite high quality.

Seedream4.0

The color tone came out dark, but I felt the consistency of the people and the balance were quite high quality.

Task 04: Seat a Man and Woman on a Sofa

The task is to edit a man and woman from separate images to appear sitting together on a sofa.

Comparison of Output Results

gpt-image-1

The composition is too close to the subjects, and the people feel a bit large in comparison to the sofa. Facial consistency does not appear to be maintained.

Gemini 3 Pro Image

At first glance it looks good, but the people are small in comparison to the sofa.

Seedream4.0

There is seemingly no problem with all the composition, balance between sofa and people sizes, and facial consistency.

Task 05: Convert English Title on a Magazine to Japanese

The task is to convert an English magazine title to Japanese.

Comparison of Output Results

gpt-image-1

The title font has become quite bold, but it does not appear to be broken. The cover page photo has also changed to the one showing a castle, giving it a Japanese feel.

Gemini 3 Pro Image

Since the model’s text generation feature was enhanced, the output is quite good. The magazine in the image even includes the Japanese subtitle below the title. Moreover, the subtitle clearly makes sense as Japanese. The cover shows cherry blossoms in full bloom alongside red autumn leaves, which is an odd seasonal mismatch.

Seedream4.0

The title font is not particularly broken, but unnecessary punctuation is inserted. Small text in the cover has broken down. The photo shows a harbor town-like location with cherry blossoms, giving it a Japanese feel.

Task 06: Change a Man's Hairstyle Based on an Illustration

The task is to restyle a man's hair to match three different hairstyles from an illustration, outputting the results side by side.

Comparison of Output Results

gpt-image-1

There seems that subjects tend to be output large. Facial consistency does not appear to be maintained. Also, the long-permed hairstyle could not be reproduced.

Gemini 3 Pro Image

The face with long permed hair leans slightly toward an illustrated look, but overall the hairstyles from the illustration have been reproduced well.

Seedream4.0

Seedream 4.0, which had shown high consistency so far, did not produce results according to instructions when it came to hairstyles.

Conducting this kind of comparative examination reveals the quirks of each, which I found very interesting. While the differences and tendencies of each model are now clearly visible, I think the models will quickly improve their accuracy to the level where these differences become indistinguishable.

Finally, about Safe Image Generation and Editing

As image editing becomes increasingly easy, the risk of unintentional misuse also grows. To this end, we should NOT:

• Produce output that infringes copyright; or
• Reference things that may infringe copyright in the generation process.

Of course, as well as these, we should also:

• Show consideration for minors and others in socially vulnerable positions;
• Protect the dignity of others from violence such as discrimination and insult; or
• Not spread misinformation through deepfakes.

I would like to take the above points in consideration when performing image generation and editing.