Generative AI

koi.photo has three optional generative AI tools: Generative Fill adds or replaces something in a selection from a text prompt, Generative Expand makes the canvas bigger and fills the new area, and AI Remove removes an object and rebuilds what was behind it. They run on cloud AI models, need a free account and use credits.

Everything else stays as it was: the editor, Select Subject, Remove Background and the local Remove tool are free, run on your device and need no account.

Local AI and cloud AICopy Anchor Link

Generative FillCopy Anchor Link

1. Make a selection around the area you want to change (any selection tool works; feather it for softer edges).
2. Choose Edit ▸ Generative Fill…, Select ▸ Generative Fill…, the Gen Fill quick action in Properties, or search for "generative fill".
3. Describe what should be there, for example "a red sailboat", or leave the prompt empty to fill the area from its surroundings.
4. Pick how many variations you want (1–4). The cost shows before you start: 1 credit per variation.
5. Click Generate. Cancel stops the request and your credits are refunded.
6. Use the arrows to flip through the variations, then Keep or Discard.

The result goes on a new layer with a mask made from your selection. Your photo layer isn't changed, so you can hide the new layer, paint on its mask or delete it later. The whole result is one step in History: one Undo removes it, whichever variation you kept.

Generative ExpandCopy Anchor Link

Choose Image ▸ Generative Expand…. Set the new canvas size (it starts 25 % wider) and where the photo sits, then click Expand…. The new area is selected and the prompt bar opens. Describe the extended scene or leave the prompt empty, and click Generate. The filled border is a new masked layer, like Generative Fill. Undo removes the fill first, then the selection of the new area, then the bigger canvas.

AI RemoveCopy Anchor Link

• With the Remove tool: choose the Remove tool (J), set Engine to Cloud AI in the toolbar and paint over the object. Each stroke uses 1 credit. Local is the free, on-device fill.
• With a selection: select the object, then choose Edit ▸ Fill ▸ Generative Remove (Cloud AI).

AI Remove writes into the same Retouch layer as the local Remove tool, so your photo stays untouched. It's better than the local fill at removing large objects in front of detailed backgrounds; for small blemishes the free local tool is usually just as good. More in Retouching.

AI assistantCopy Anchor Link

The assistant edits your document from plain-language requests, for example "add a title saying Summer Sale and make the background darker" or "convert the photo to black and white". Open it with Window ▸ Assistant (⇧⌘J, Ctrl+Shift+J on Windows), or type a request into command search and pick Ask the assistant.

• It works with koi's normal tools: layers, adjustment layers and live filters, text, shapes, selections (including Select Subject and Remove Background), cropping and the canvas size. It can't paint, generate images, open or save files, or browse the web.
• Each change shows as a chip in the chat ("Added Exposure adjustment"). Click a chip to select the layer it changed.
• Everything one request did is one step in History: a single Undo reverts it all.
• Stop ends the request; changes made so far stay and can be undone.
• Export opens the Export dialog; you confirm the download yourself.
• Each request you send uses 1 credit, however many changes the assistant makes for it.
• View-only collaborators can't use it on a shared document.

What the assistant sees: your messages and a short description of the document: its title and size, and the list of layers with their names, kinds, visibility and which are selected (plus the first words of text layers). Your pixels are never sent, so it can't look at the photo; describe what you want. The request goes through Vercel's AI Gateway to a language model provider. koi.photo doesn't store the conversation; it disappears when you reload the page or click New chat.

CreditsCopy Anchor Link

• A free account comes with 50 credits a month. 1 credit = 1 generated image, whichever tool you use.
• Credits reset on the 1st of each month (UTC). Unused credits don't carry over.
• If a request fails, is cancelled or is declined by the model, the credits go back to you.
• Account ▸ Account Settings… ▸ AI usage shows this month's credits and your latest requests.
• When your credits run out, the prompt bar says so and the cloud tools wait until the next month. The local tools keep working.

There's also a daily limit across all users that keeps the service affordable. If it's reached, cloud AI pauses until the next day.

Privacy: what is sent whereCopy Anchor Link

When you click Generate (or finish an AI Remove stroke), koi.photo sends:

• a copy of what's visible in the area around your selection, scaled to at most 1024 pixels on its longest side,
• a black-and-white mask of the selection,
• your prompt.

Nothing else from your document is sent: nothing outside that area, not the file name, not your other documents. The request goes through Vercel's AI Gateway to the model's provider: Black Forest Labs (FLUX Fill) for Generative Fill and Expand, Google (Gemini) for AI Remove. Their terms for API use apply to that request.

koi.photo doesn't store the image, the mask or your prompt. It keeps a usage record (which tool, when, how many credits and an estimated cost) for your credit balance and the AI usage page. Deleting your account deletes those records.

LimitsCopy Anchor Link

• Results are generated at up to about 1 megapixel and scaled to your selection, so a very large selection looks softer than the rest of the photo. Use smaller selections for detail.
• The model may decline a prompt. Prompts that sexualise minors are refused before any model sees them.
• Generative AI needs an internet connection and a signed-in account; guests in a shared document can't use it.

QuestionsCopy Anchor Link

Is generative AI free? It's included with the free account, up to 50 images a month. There's no paid plan.

Does Generative Fill change my photo? No. The result is a new layer with a mask. Delete or hide the layer to get back to the original.

Can I use generative AI without an account? No. Credits are tied to an account. Everything else in koi.photo works without one; see Free & private.