JSFiddle - React, Tailwind, and code Playground
HTML
<input type="checkbox" id="1" class="box">checkbox1</input><br>
<input type="checkbox" id="2" class="box">checkbox2</input><br>
<input type="checkbox" id="3" class="box">checkbox3</input><br>
<input type="checkbox" id="4" class="box">checkbox4</input><br>
<input type="checkbox" id="5" class="box">checkbox5</input><br>
<input type="checkbox" id="6" class="box">checkbox6</input><br>
JavaScript
let boxes = document.getElementsByClassName('box').length;
function save() {
for(let i = 1; i <= boxes; i++){
var checkbox = document.getElementById(String(i));
localStorage.setItem("checkbox" + String(i), checkbox.checked);
}
}
//for loading
for(let i = 1; i <= boxes; i++){
if(localStorage.length > 0){
var checked = JSON.parse(localStorage.getItem("checkbox" + String(i)));
document.getElementById(String(i)).checked = checked;
}
}
window.addEventListener('change', save);