Real lenses cannot focus every wavelength at exactly the same point, so colour fringes appear toward the edges of a frame — cyan and magenta halos along high-contrast lines. Photographers usually correct it; artists exaggerate it.
Open the chromatic aberration tool →Free · no sign-up · runs in your browser — your photo is never uploaded.
This tool separates the red, green and blue channels either radially, mimicking a real lens, or linearly along an angle you choose, which reads as digital glitch rather than optical error.
It is a lens defect where different colours of light focus at slightly different points, producing coloured fringes along edges. It can be simulated deliberately as a stylistic effect.
Separate the red, green and blue channels spatially. This tool does it radially or linearly with an adjustable amount, free in your browser.