When Livereload is too much and cmd-tab’ing too little, there’s always this AppleScript.
#!/bin/sh osascript -e 'tell application "Safari" set _url to URL of current tab of front window set URL of current tab of front window to _url end tell'
Put it in your PATH, chmod it +x, and map it to what you like in vim:
map ,r :call system("update_safari.sh")
You could even auto-run it when you save the current buffer:
autocmd BufWritePost <buffer> :call system("update_safari.sh")
* to do it in every buffer.