JSFiddle - React, Tailwind, and code Playground

HTML

Don't forget to -256 to get actual id before write in config files!
<textarea id="input"></textarea>
<button id="start" onclick="start()">Start</button>
<textarea id="output"></textarea>

CSS

textarea{
	display: block;
	width: 400px;
	height: 200px;
}

JavaScript

var suggest = "";
var output = "";
  
function start(){
  var a=document.getElementById("input").value;
  var b=document.getElementById("output");
  
  console.log("start");
  a=a.split("\n");
  var left=-1;
  var right=-1;
  output = "";
	suggest = "";
  //console.log("a.length: "+a.length);
  for(var i=0;i<a.length;i++){
		var t=a[i].split(",");
		var c=t[0]*1;
		if(!c && t[0]!="0"){
			//console.log("not number");
			continue;
		}
		
		if(left == -1){
			left = c;
			right = c;
		}else	if(c == right+1){
			right = c;
		}else{
			/*
			if(!confirm("left: "+left+" right: "+right)){
				return;
			}
			*/
			
			printlr(left,right);
			left = c;
			right = c;
		}
  }
	printlr(left,right);
	

  output = "Suggest range:\n" + suggest + "\nAll:\n" + output;
  b.value = output;
  
  console.log("end");
}

function printlr(l,r){
	if(l == r){
		output += l + "\n";
	}else{
		output += l + "~" + r + "\n";
		if(r - l >= 200){
			suggest += l+"~"+r+" ("+ (r - l) +" ids)\n";
		}
	}
}