How to Make High Resolution Images in GIMP

thanks
is ti possible to upscale multiple images at once ?

Use a combination of sharpening and saving the image at 100 quality as it usually defaults to 90. Many images won't tolerate resizing.

can u tell me as point by point to do

Simple and clear

thank you, but that's just resizing the image.

Bingo ! : )
Thx.

Short and to the point! Thanks!

Thanks for showing how to change image size