How can I remove this white line?

[sharp wolf]

Hello I was doing portal effect and i look this white line how to remove that

[quartz halo]

Depends on how you doing this. If it's a Layer Mask, you can try feathering the edge of the Mask. If not, you can add a mask and use Refine Mask to do it.

[sharp wolf]

Thank It's working

[dusk roost]

Gave +1 Creative Carma to @quartz halo (current: #2 - 2767)

[zealous owl]

if you have this all-round i recommend using remove white-matting and defringe

also very useful

instead of manually doing it