You applied a style, the overall look is right, and then you zoom in. There is a pale outline around the subject like a bad Photoshop cutout. The sky has visible staircase steps instead of a smooth gradient. Faces have gone soft and slightly plastic. All three of these are normal, all three are fixable, and none of them mean you have to throw the result away and start over. Learning to name the artifact is most of the battle - once you know it is a halo and not "the model being bad," you know what to change. You can reproduce all three cases on the online converter with a single portrait and a busy background.
Why halos happen
A halo is what you get when the edge of your subject gets treated differently from the pixels just outside it. The model decides the edge belongs to the style you are applying, but the background next to it does not, so you get a bright or dark rim tracing the silhouette.
The usual culprits: a very busy or high-contrast background, a subject with fine detail like hair or tree branches, or a style strength pushed too high. If the style is strong enough to repaint texture, it will also repaint the gap between two textures.
Frequency matters too. Halos are much more visible on images where the subject is small relative to the frame, because the rim occupies a larger share of the subject's total area.
Fixing halos
Try these in order, cheapest first.
Lower the strength. This is the fix people skip. Dropping strength by ten or fifteen percent often removes the rim entirely while keeping the look you liked.
Mask the subject. If your tool supports it, keep the original pixels inside the subject and only apply the style to the background, or the reverse. Halos mostly live at the boundary, so controlling which side of the boundary gets processed makes them disappear.
Clean up in the editor. A healing brush set to a small size, run along the rim at fifty percent opacity, is enough for most cases. Do not use a hard clone stamp - you will trade a halo for a visible patch.
What causes banding
Banding is a gradient that has been quantized into visible steps. It shows up most in skies, studio backdrops, and skin. Two things cause it: heavy compression during processing, and a style that pushes colors into a narrow range so subtle transitions get rounded to the nearest available value.
It is worth checking whether the banding was in your source file before you blame the style pass. Open the original at 100 percent and look at the same area. If the steps are already there, no amount of re-running will help.
Fixing banding
Add a tiny amount of noise. Genuinely, this is the standard fix - a very light grain layer breaks up the steps so the eye reads the gradient as smooth again. Keep it subtle enough that you would not notice it at full size.
If the banding is severe, the practical answer is to lower the resolution of the final render and upscale afterward with a light dither applied, rather than trying to fix a badly quantized large file.
Mushy detail: the one you cannot fully fix
Once fine detail has been dissolved by a style pass, no amount of sharpening brings it back - sharpening just makes the mush crisp. What you can do is protect it up front: mask out eyes, jewelry, text, and faces before applying the style, then composite the sharp originals back in afterward.
This is the single highest-value habit in this whole workflow. Anything the viewer's eye goes to first should never be inside the area being restyled.
Work at higher resolution than you need
Every artifact in this article gets worse as resolution drops, because the model has fewer pixels to work with at each edge. If you are producing something for print or for a large screen, run the pass at the largest size your tool allows and downscale the result. The artifacts shrink with everything else and become genuinely invisible.
The same logic applies to the source. Feeding in a small, compressed image and expecting a clean large result is the most common mistake in this whole process - the upscaling has to invent detail that was never captured, and invented detail is exactly where halos and mush come from.
Ready to test these fixes on your own files? Start on the image transformation page and run one pass at your usual settings, then repeat with reduced strength and a mask on the subject. Comparing the two side by side is the fastest way to see which artifact you were actually fighting.