media library: does size matter?

Question: do the unused images in the Library affect the site loading speed? Is it best practice to remove them until needed?

No and no.

Although I can edit images once in the Library, is it better to reduce them prior to uploading to the Library?

Yes, in that very large images (large in terms of pixels, not in terms of filesize) take up more memory when processing them, so they process much slower. But, they only have to process once, when you upload them or when you use the editor for them. After that, they don’t affect site speed one bit.

Thanx for the comments. I have gone ahead and installed EWWW image(name??) and it did optimize the images. I assume effectively. Prior to that I did guess at smaller image sizes and resized them smaller in the Library image editor. I see a new smaller pixel as a result…and still wonder if I had uploaded a smaller original image size, would I have a better result for my site loading time… any ideas on that.

This is all prompted by a recent Google speed test that really complained loudly about needing to compress the image size…among so many other issues.