I have downloaded OptiFine from OptiFine.net how ever it doesn't seem to work. Whenever I download I double click and hit install. A message pops up that I have installed it. Then I load up the launcher and a new option in the installation appears labeled "OptiFine". I select this, hit save and load up the game. After loading a world, and even creating a new one, Minecraft looks the same. I have tried uninstalling the launcher and re installing, I have also tried deleting all OptiFine files within .minecraft folder then reinstalling OptiFine. I have tried other versions of OptiFine with the same result. Does anyone know how to resolve this issue? Related screenshots attached.
Versions matter for Modloaders (Forge, Fabric, Rift, Liteloader), mods and more (while you can use Resourcepacks and Worlds in other versions it isn't recommended).
If you want Optifine to work use 1.14.4 not 1.15.1.
Optifine will be ready for 1.15/1.15.1 when it is ready.
If Optifine took a few months to be ready for 1.14 versions expect the same for 1.15.
Besides 1.15 runs better so it shouldn't be that bad compared to 1.14 (I can't even run Forge 1.14.4 without it being awkward but in 1.15 it isn't a problem even if Forge 1.15 is in Beta still and Fabric I've never had issues with in either 1.14/1.15).
If you want mods for 1.15.1 that improve performance look around. Dynamic FPS for Fabric is for 1.15.1 and others for Forge might exist I just don't remember their names off the top of my head.
Check my forum threads in my signature and if you find anything that improves performance try them out.
Hmm Optifine should work, it's just downloading Optifine from it's official website: https://optifine.net/downloads and double clicking to install it (other methods like extracting are more so for modloaders like Forge & Fabric not Vanilla (unmodded)).
Did you have any issues with Optifine 1.14.4 versions besides F5? I tried F5 myself just now and had no issues, even in a new world, nothing was out of the ordinary. Can I see your .minecraft instance just encase.
Do you have Java installed before attempting this?