Is there a limit to the size of my nether portal?

I made this nether portal. Is it too big, or am I doing something wrong. I barely got it in one screenshot.

2 Answers

This is far too big.

The portal dimensions you can use are between the following (for the obsidian frame):

Minimum: 4x5

Maximum: 23x23

It also doesn't need to have corners.

The Nether Portal that you are building is too big as prior to the 1.7 update, only Portals sized 21x21 (I think so!) are allowed to be lit up and be used. So, make it smaller.