Face Swap with Gemini, Nano Banana and ChatGPT
You can face swap with Gemini (its image model is called Nano Banana) or with ChatGPT by uploading both photos and asking it to put the face from one onto the other while keeping everything else. It works often enough to be worth a try. These chatbots redraw the whole picture, though, so the face can come back looking like a relative of the person rather than the person, and small details elsewhere change too.
Here is the prompt that gives the most consistent results, what tends to go wrong, and how to choose between a chatbot and a dedicated face swap tool.
How to face swap with Gemini (Nano Banana)
- Open Gemini and start a new chat. Image editing works on the free plan, with a daily limit.
- Upload two photos: first the photo you want to change, then the photo with the face you want.
- Paste a prompt that says what to change and, just as important, what to keep (below).
- If the face drifts, reply with one correction at a time, for example "make the eyes and nose closer to image 2 and change nothing else".
Prompt: Replace the face of the person in image 1 with the face from image 2. Keep the pose, hairstyle, hairline, clothing, lighting, background and framing of image 1 exactly as they are. Copy the eye shape, nose, mouth, jawline and skin texture from image 2.
The keep-list matters. With a short prompt like "swap the faces", Nano Banana often swaps the hair and sometimes the whole person.
How to swap faces with ChatGPT
The method is the same: upload both photos and use the prompt above. Expect more pushback. OpenAI's rules don't allow editing images of real people without their consent, and ChatGPT may decline a swap when the photos show real people, or return a face that only loosely resembles the source.
When it does go through, ChatGPT generates a new image instead of editing yours, like Gemini. Small things shift as a result: text in the background, fingers, the pattern on a shirt.
Why AI chatbots change the face, and the rest of the photo
Gemini and ChatGPT are image generators. They look at your photos and draw a new picture that follows your instructions, so details you never asked them to touch can move. A good prompt reduces this, but there's no setting that locks the original pixels.
A face swap model works the other way round. It finds the face in the target photo, replaces that region with the face from your selfie and blends the edge. When we compared four swaps from our own templates with the original photos, under 1% of the pixels had changed, and every one of them was inside a box around the face.
Gemini vs ChatGPT vs a face swap model
| Gemini (Nano Banana) | ChatGPT | Face Swap AI | |
|---|---|---|---|
| What changes | The whole image is redrawn | The whole image is redrawn | Only the face area |
| Prompt needed | Yes, with a keep-list | Yes, with a keep-list | No |
| Can refuse | Sometimes | Sometimes | Only when it finds no face |
| Marks on the image | Invisible SynthID and C2PA data; visible sparkle optional since August 2026 | C2PA data | None |
| Cost | Free with daily limits | Free with limits, more on paid plans | $2.99 for 15 swaps |
Which one should you use?
Use Gemini or ChatGPT when you want the AI to invent part of the scene as well, such as a new outfit or background along with the face, and you don't mind a few tries. Use a face swap model when the target photo has to stay exactly as it is, when the face must be clearly recognizable, or when you want the same result every time.
For a ready-made scene, 50+ templates are lit and framed for swaps. For full manual control, see how to swap faces in Photoshop.
Questions
Is it legal to face swap someone with Gemini or ChatGPT?
Swapping your own face, or a friend's with their agreement, is fine for personal use in most places. Using someone's face without permission breaks Google's and OpenAI's rules, and sharing sexual deepfakes of real people is a criminal offence in the UK and the US, among other countries.
What is the best Nano Banana face swap prompt?
One that lists what to keep. Name the photo to change and the photo to take the face from, list the features to copy (eye shape, nose, mouth, jawline, skin texture) and everything that must stay (pose, hair, clothes, lighting, background).
Keep reading
How to swap faces in Photoshop
Swap faces in Photoshop with Auto-Blend Layers: select, align, blend and color-match in 8 steps. Plus a one-click way if you don't have Photoshop.
8 tips for a realistic face swap
Why some face swaps look fake and how to fix it: angle, light, sharpness, expression, hair, glasses and skin tone. Eight tips for any AI face swap app.
Best AI face swap app: a checklist
How to pick the best AI face swap app: realism, templates, watermarks, price, privacy and speed. A 7-point checklist, and how Face Swap AI scores.