Is there any way to remove the black bars at the top and bottom while also keeping the image sharp? I tried turning off Pixel_Perfect, but I can see the image get a little bit blurrier. I'm on a PC and trying to scale up on a 4K monitor.

How big are the bars? If your vertical resolution isn't a multiple of 128, it's impossible to have pixel-perfect scaling.

The bars are around half an inch thick. Since most people are using 1080p, 1440p or 2160p monitors, then I am assuming that nobody is getting pixel perfect scaling and everybody has those top and bottom black bars?

When I turn off Integer Scaling in Retroarch, the pixels are still sharp and fills out the top and bottom bars. Pico-8 doesn't have this type of scaling?

I'm not sure what you mean, it's impossible for the pixels to be sharp and evenly-sized if it's not a multiple of 128.

I never said the pixels were evenly-sized on Retroarch. I said the pixels were still sharp and there are no top and bottom bars. Some pixels could be a bit rectangular, but on a 4K monitor you don't notice it. That's why most people turn off Integer Scaling on a 4K monitor.

However, on Pico-8, the pixels do not stay sharp when it tries to fill out the top and bottom bars. The pixels are a bit blurry. So that's why I am asking if Pico-8 has the same type of scaling that Retroarch has in my previous post.