Where is the thumbnail?

When you upload an image you normally see a thumbnail of the image and you can use that as a link to the larger image. If it is missing the image is too big.

An image should be 2000 pixels on it’s longest side and you will get a thumbnail.

To resize an image, check this page for optimizing images.

But, if you want to use a thumbnail and have it appear inside your theme as a page and for it to fit, you need to set the width of the image before you upload it. Check this page on how big the images can be to fit your theme nicely.

If you upload images straight from a digital camera you will have problems unless you study the above.

(You can upload images of any size if you do not mind about a thumbnail. But they look bad when someone clicks on the link. Try this image link - it’s 2592*1944 and 2.5mb. You don’t want to make people do this)