How to make a images resolution smaller but keep the good quality (with photoshop)

hi guys dose any1 know how to make a image resolution smaller but keep it good quality and vice versa. (with photoshop)?

Vive versa means bigger image and poor quality? That’s a built-in feature :wink:

To make image smaller and still looking quite good, I use the “Unsharp Mask” filter (amount 20%, radius 1, threshold 0), sometimes twice.
Then some contrast/levels adjustments and in most cases the result is really good.

when changing the resolution of an image just turn off bicubic resampling under image size.

That works well. I’ve used just Sharpen Edges too like when scrunching images down to thumbnail size.