How to write AI image edit prompts: change one thing, keep the rest

The most common mistake with an edit model is to treat it like a text-to-image model. You upload a photo of a living room, then type the whole scene again: "a cosy living room with a grey sofa, a wooden floor, a green armchair by the window". The model reads that as a request for a new picture that happens to resemble yours, and it redraws everything. The armchair turns green, and so does half the wall.

An edit prompt works the other way round. The picture already describes itself. Your words only need to say what changes and what does not. Think of it as a short work order handed to a retoucher, not a scene description handed to a painter.

The three parts of a work order

1. 01The change. One verb and one object: replace, remove, add, recolour, move. "Replace the grey sofa with a dark green velvet one."
2. 02The place. Where in the picture, in plain words: "on the left", "behind the woman in the red coat", "the second bottle from the right". Edit models have no pointer, so position is something you say.
3. 03The lock. What must stay exactly as it is: "Keep the floor, the window, the light and the camera angle unchanged." This is the line most people leave out, and it is the one that stops the model from tidying up things you never asked it to touch.

Why one change per round

Ask for three things at once (a new sofa, a lamp on the table, evening light) and two things happen. The model has to rebuild more of the picture, so more of what you liked drifts. And when the result is wrong, you cannot tell which instruction caused it. One change per round costs more renders on paper, but each round is easy to judge, and you stop paying for rounds that fail for reasons you cannot see.

Order the rounds from big to small. Structure first (remove the chair, swap the background), then colour and material, then light, then the small fixes. A light change made before a background swap is a light change you will have to make again.

Words that help and words that hurt

• Name things the way they look, not what they mean to you. "The white mug with a chipped rim" finds the mug; "my favourite mug" finds nothing.
• Describe what you add as if it belongs there. "Add a brass floor lamp behind the armchair, lit, matching the warm light already in the room" blends in. "Add a lamp" gets a lamp that looks pasted on.
• Avoid improvement words like "better", "nicer", "more professional". They give the model permission to change anything, and it will.
• Ask for subtle when you mean subtle. "Slightly warmer", "a little less clutter on the desk". Edit models tend to overdo a change unless you set the size of it.

Doing it in the studio

Open the models page and look for the image-to-image type: these are the models that take your picture as input. Choose one, attach your file with + Image in the composer, write the work order in the prompt and check the price on the Generate button before you press it. Some edit models take a single image, others take several, so you can add a second picture as a reference for the new sofa or the new shirt. The model page lists which inputs it takes.

To edit something you rendered in the studio, download it from the session feed in the studio or from your library first, then attach it the same way. Keep the original: if round three goes wrong, you go back to round two's file, not to the start.

Some jobs have their own tools rather than a general edit model. Background removal and object removal are model types of their own in the catalog, and a few image-to-image models are built for a single job, such as relighting a scene or restoring an old photo. When one of those fits, it is usually the safer choice, because it was made to do that one thing and leave the rest alone.

When the edit keeps touching the rest

Sometimes a lock line is not enough and faces shift, colours move or the crop changes slightly with every round. Try, in this order: shorten the instruction to the change and the lock alone; name the things that moved in the lock ("keep her face, hair and expression unchanged"); check whether the model has an aspect ratio setting and leave it matching your source, since a new shape forces a new layout; then try a different edit model, because they differ a lot in how much they preserve. If the picture still drifts, re-roll the original instead, as the hands and text guide suggests for small details.

What an edit model cannot do

There is no brush in the studio. You cannot paint over the area you want changed; the model decides what your words point at. A few edit models accept a mask image as an extra input, but you have to make that mask in another program. An edit is also never a guaranteed pixel-for-pixel copy of what you said to keep: most models redraw the whole picture and try to hold the locked parts steady, so fine texture, small text and faces can shift a little. For a series that must stay identical across many pictures, a reference image does a different job, covered in the reference guide. And every round is a full render with its own price, so ten timid rounds cost more than three clear ones.