Flux Kontext prompts for editing work differently from generation prompts. The model reads your reference image first, then applies only the changes you describe. You don't rebuild the scene from scratch. You push on specific elements while the rest stays locked. Here are 8 editing prompts with what to check in each result. On 8frame, Flux editing comes as Flux Edit on FLUX.2 [pro] (7 credits for an image around one megapixel, more for larger inputs) and Kontext Max (13 credits flat).
Correction, 2026-09-30: the first version of this page presented these prompts as run in 8frame sessions, with results, retries and thresholds we cannot reproduce, and mentioned a feather mask; 8frame has no mask tool. The prompts and the formula stay; the rest is gone.
TL;DR
- Flux Kontext is a reference-driven model: describe the change, not the whole image
- Specify what stays the same as explicitly as what changes
- On 8frame: Flux Edit from 7 credits, Kontext Max 13
- Crop before editing: Flux Edit is priced on the input's size
When to use Flux Kontext for editing existing images
Kontext is the right pick when the base image is solid and you want surgical changes: swap a studio background for a city street, add a product to a lifestyle shot, shift noon light to golden hour. It does those without rebuilding from scratch.
Start from the best source image you have; heavy compression makes it harder to separate subject from background. For a comparison of image models, see Nano Banana vs Seedream vs Flux.
The prompt formula
The most reliable structure is: [Keep anchor] + [Target change] + [Technical constraint]
Keep anchor: what must not change. "Keep the subject's face, expression, and jacket unchanged" outperforms "keep the person the same."
Target change: the modification, precisely. "Replace the white wall with a rain-slicked Tokyo street at night, neon reflections in the wet pavement" beats "change the background to something urban."
Technical constraint: lighting match or what must not change. Shape is a node setting.
8 prompts for editing existing images
1. Background swap, subject preserved
Prompt: Keep the subject's face, hair, jacket, and pose exactly as in the reference image. Replace the plain grey studio background with a sun-lit alpine meadow, mid-afternoon light matching the existing front-lit exposure on the subject. No shadow inconsistency between subject and new background.
What to check: That the subject is untouched (face, hair, jacket, pose) and that the light on the subject matches the new background.
2. Lighting: time-of-day change
Prompt: Reference image: portrait of a woman standing on a city sidewalk, shot at noon with flat overhead light. Shift the lighting to golden hour: warm amber directional light from camera-left, soft fill from a reflector on the right, long shadow on the pavement behind her. Keep her clothing and expression unchanged.
What to check: That both subject and background shift temperature, shadows fall where described, and hair keeps its natural colour. If hair turns orange, add "hair retains natural color, only lit by warm ambient".
3. Outfit change
Prompt: Keep the subject's face, skin tone, and pose exactly as in the reference. Replace the grey hoodie with a fitted dark navy blazer, white dress shirt visible at the collar, no tie. Maintain the original background. Fabric should have a natural matte texture, not shiny.
What to check: Fabric texture (the "matte, not shiny" note matters) and the edges where sleeves meet wrists. Adding "sleeves extend to the wrist" helps.
4. Object removal
Prompt: Remove the coffee cup from the table in the lower-right corner of the frame. Fill the space with the same wooden table surface, matching grain direction and ambient light. Do not alter anything else in the frame.
What to check: That the filled area continues the wood grain and shadow instead of leaving a soft patch. Large objects are harder to remove cleanly than small ones.
5. Object addition
Prompt: Add a black matte espresso cup on the wooden table in the lower-left foreground, empty, no lid, steam rising gently. Cup should cast a soft shadow consistent with the diffuse overhead light already in the scene. No changes to anything else.
What to check: Size and shadow of the new cup. If the size is off, describe it relative to other objects in the frame.
6. Color regrade
Prompt: Apply a desaturated, cool-toned grade to the entire image: lift the shadows toward cool blue-grey, pull the highlights toward pale white with a slight cyan tint, reduce overall saturation by about 30%. Preserve skin tone detail, slightly warmer than the surroundings. No change to composition or sharpness.
What to check: Skin staying warmer than the surroundings. Treat "about 30%" as a direction, not a measurement.
7. Style transfer onto existing photo
Prompt: Apply a hand-painted oil painting style to the reference photograph, as if rendered by a contemporary realist painter: visible brushstrokes, especially in the sky and background foliage, slightly thickened paint texture. Keep the subject's facial structure and likeness recognizable, face rendered with finer detail than the background. Maintain the original color palette, do not shift hue.
What to check: Likeness in the face. "Facial structure and likeness recognizable" is the line doing the work; without it, faces can simplify.
8. Composition extension (outpainting)
Prompt: Extend the canvas to the left by approximately 40% of the current image width. Fill the new area with the same indoor environment visible in the original: matching wall color, light direction from camera-right, floor visible at the bottom of the frame. No subject should appear in the new area. The seam between old and new canvas should be invisible.
What to check: The seam between old and new areas, especially where there are strong lines or patterns at the edge. 8frame has no mask tool, so if a seam shows, simplify the background near the edge or crop.
Common failures and fixes
Subject bleeds into background change. Add "do not alter the subject's color, texture, or outline" to the keep anchor.
Lighting inconsistency after background swap. State the existing key light direction explicitly and require the new background to match it.
Object additions appear too large or too small. Include a size reference relative to other objects in the frame rather than an absolute dimension.
Style transfer loses identity. Add "maintain facial likeness and recognizable features, apply style more heavily to background than subject."
Seams on patterned backgrounds. Add "the seam should be invisible, background pattern continues uninterrupted", and check the edge at 100%.
Step-by-step on 8frame
- Open the 8frame canvas and upload the image you want to edit.
- Add a Flux Edit node and choose FLUX.2 [pro] (from 7 credits) or Kontext Max (13).
- Write your prompt using the keep anchor + target change + technical constraint structure.
- Run the first pass and compare it with the original side by side on the canvas.
- For iterative edits (outfit change followed by background swap, for example), chain two Kontext nodes. Separate tasks produce cleaner separations than stacking both edits in one prompt.
- Export, or enlarge with BRIA upscale (6 credits, 2x or 4x) if you need more pixels.
FAQ
What makes Flux Kontext different from regular image generation prompts?
Kontext reads the reference first and builds the output as a modification. You describe the change relative to what exists. Subject identity and scene geometry carry over without being re-specified.
Can Flux Kontext change someone's face or identity?
Yes, if you don't anchor it. Phrases like "keep the subject's face, expression, and skin tone unchanged" lock identity during non-face edits.
How many edits can I stack in one prompt?
Two or three related changes usually work fine. Background swap plus lighting is fine. Background swap plus outfit plus style transfer plus outpainting in one pass produces inconsistent results. For complex sequences, chain separate Kontext nodes rather than stacking everything into one prompt.
For a head-to-head comparison of Flux Kontext against Nano Banana and Seedream on image generation tasks, see nano banana vs seedream vs flux.
Sources
- 8frame Flux Edit and Kontext Max prices: the 8frame tool registry, 2026-09-30
Say what stays, say what changes, check the edges. The 8frame canvas is free and unlimited; generation is paid from $19/month.