How to make the background of a gif image transparent

Question

I guess there would be two ways to do this:

1. Select all layers and then use Magic Eraser to make bg color transparent(I tried this and photoshop doesn't allow you to erase bg from multiple layers at the same time)

2. Make one of the layers the Background Layer and then all other layers background would be the same color as the Background Layer.
The point at the second option is I don't know how to change the background color picker to "Transparent"?

Perhaps there are other ways to Make gif image's background transparent and I didn't mention; I'll be appreciate that if you say how to do this.

Answer 1

Assuming you’re starting with a GIF or Photoshop frame animation, with the frames already set up, the easiest way is to create a group with a mask.

To do this, select all the layers and press ⌘G (or Layer → New → Group from Layers). From there, you can create a bitmap mask for the group by choosing Layer → Layer Mask → Reveal All. Paint on the group with black to mask portions of all the frames.

Answer 2

I would go about it by creating a mask layer and masking the area you want to be shown by painting white on the layer. I'd then copy the mask to each layer and apply it. You'll know you're done when the checkerboard background appears, it will indicate transparency. To finish I would save as GIF file.

Answer 3

Well, I don't have much experience with photoshop, but from the research I've done, you might just have to erase the backgrounds one by one.