Is a Canon Powershot sx40 is better? Or a nikon d3100?

Should i save up a little extra for the d3100? Or just go with the sx40? Does anyone have any experience with em?

The Canon sx40 isn't a dSLR so you are making an apples and oranges comparison.

The sx40 at its core, is just a cheap compact camera. It has the same tiny image sensor found in cheap compacts. It has a larger body, some extra controls but that's about it. The only real advantage that small image sensor cameras have is the megazoom. On the downside, the image quality is terrible, especially in low light.

The Nikon is a real dSLR with a very large image sensor. Save up, any dSLR is better than a megazoom.

I prefer Nikon D3100 over Canon SX40. Simply because Nikon D3100 is one of the best entry-level digital slr camera and the price is affordable.

Save for Nikon D3100 its a better one