how to install ?

[elig0n]

I installed via vim-plugged (similar to Vundle) but seems like it's not working because it does not show the distinct keyword/value highlights.
I also tried manually copying all the files from the directories (syntax, indent, ft*) to their equals from ~/.vim/ with no success either.

[juanMarinero]

To install: https://vimawesome.com/plugin/json-vim
With VimPlug works.

Maybe another plugin interacts, just comment all other Plugin in ~/.vimrc and source it. If then vim-json works, uncomment little by little till you find the troublemaker.

To disable plugin once installed: let g:vim_json_syntax_conceal = 0

[juanMarinero]

readme.md#common-problems

It's a good idea to test drive with the files json-test.json and jsonp-test.jsonp first thing.

Check also that let g:vim_json_syntax_conceal = 1 in your vimrc, otherwise ftplugin sets conceallevel=0

if has('conceal')
	if (g:vim_json_syntax_conceal == 1)
		"level 2 means concealed text gets completely hidden unless a
		"replacement is defined (none is defined by us)
		setlocal conceallevel=2
		let &l:concealcursor = g:vim_json_syntax_concealcursor
	else
		"level 0 means text is shown normally = no concealing
		setlocal conceallevel=0
	endif
	"maybe g:vim_json_syntax_conceal could be settable to 0,1,2 to map
	"directly to vim's conceallevels? unsure if anyone cares
endif