In this tutorial, I will teach you how to create a Todo List app using HTML5, CSS3, and JavaScript. The complete source code of this JavaScript to-do list app is given below.
You can download the full source code (including images) of this JavaScript todo list app at the end of this article.
HTML5, CSS3, JavaScript Todo List App Source Code
index.html
<!DOCTYPE html> <html lang="en" dir="ltr"> <head> <meta charset="utf-8"> <title>Todo List App in JavaScript</title> <link rel="stylesheet" href="style.css"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <!-- Iconscout Link For Icons --> <link rel="stylesheet" href="https://unicons.iconscout.com/release/v4.0.0/css/line.css"> </head> <body> <div class="wrapper"> <div class="task-input"> <img src="bars-icon.svg" alt="icon"> <input type="text" placeholder="Add a new task"> </div> <div class="controls"> <div class="filters"> <span class="active" id="all">All</span> <span id="pending">Pending</span> <span id="completed">Completed</span> </div> <button class="clear-btn">Clear All</button> </div> <ul class="task-box"></ul> </div> <script src="script.js"></script> </body> </html>
script.js
const taskInput = document.querySelector(".task-input input"), filters = document.querySelectorAll(".filters span"), clearAll = document.querySelector(".clear-btn"), taskBox = document.querySelector(".task-box"); let editId, isEditTask = false, todos = JSON.parse(localStorage.getItem("todo-list")); filters.forEach(btn => { btn.addEventListener("click", () => { document.querySelector("span.active").classList.remove("active"); btn.classList.add("active"); showTodo(btn.id); }); }); function showTodo(filter) { let liTag = ""; if(todos) { todos.forEach((todo, id) => { let completed = todo.status == "completed" ? "checked" : ""; if(filter == todo.status || filter == "all") { liTag += `<li class="task"> <label for="${id}"> <input onclick="updateStatus(this)" type="checkbox" id="${id}" ${completed}> <p class="${completed}">${todo.name}</p> </label> <div class="settings"> <i onclick="showMenu(this)" class="uil uil-ellipsis-h"></i> <ul class="task-menu"> <li onclick='editTask(${id}, "${todo.name}")'><i class="uil uil-pen"></i>Edit</li> <li onclick='deleteTask(${id}, "${filter}")'><i class="uil uil-trash"></i>Delete</li> </ul> </div> </li>`; } }); } taskBox.innerHTML = liTag || `<span>You don't have any task here</span>`; let checkTask = taskBox.querySelectorAll(".task"); !checkTask.length ? clearAll.classList.remove("active") : clearAll.classList.add("active"); taskBox.offsetHeight >= 300 ? taskBox.classList.add("overflow") : taskBox.classList.remove("overflow"); } showTodo("all"); function showMenu(selectedTask) { let menuDiv = selectedTask.parentElement.lastElementChild; menuDiv.classList.add("show"); document.addEventListener("click", e => { if(e.target.tagName != "I" || e.target != selectedTask) { menuDiv.classList.remove("show"); } }); } function updateStatus(selectedTask) { let taskName = selectedTask.parentElement.lastElementChild; if(selectedTask.checked) { taskName.classList.add("checked"); todos[selectedTask.id].status = "completed"; } else { taskName.classList.remove("checked"); todos[selectedTask.id].status = "pending"; } localStorage.setItem("todo-list", JSON.stringify(todos)) } function editTask(taskId, textName) { editId = taskId; isEditTask = true; taskInput.value = textName; taskInput.focus(); taskInput.classList.add("active"); } function deleteTask(deleteId, filter) { isEditTask = false; todos.splice(deleteId, 1); localStorage.setItem("todo-list", JSON.stringify(todos)); showTodo(filter); } clearAll.addEventListener("click", () => { isEditTask = false; todos.splice(0, todos.length); localStorage.setItem("todo-list", JSON.stringify(todos)); showTodo() }); taskInput.addEventListener("keyup", e => { let userTask = taskInput.value.trim(); if(e.key == "Enter" && userTask) { if(!isEditTask) { todos = !todos ? [] : todos; let taskInfo = {name: userTask, status: "pending"}; todos.push(taskInfo); } else { isEditTask = false; todos[editId].name = userTask; } taskInput.value = ""; localStorage.setItem("todo-list", JSON.stringify(todos)); showTodo(document.querySelector("span.active").id); } });
style.css
/* Import Google Font - Poppins */ @import url('https://fonts.googleapis.com/css2?family=Poppins:wght@400;500;600;700&display=swap'); *{ margin: 0; padding: 0; box-sizing: border-box; font-family: 'Poppins', sans-serif; } body{ width: 100%; height: 100vh; overflow: hidden; background: linear-gradient(135deg, #4AB1FF, #2D5CFE); } ::selection{ color: #fff; background: #3C87FF; } .wrapper{ max-width: 405px; padding: 28px 0 30px; margin: 137px auto; background: #fff; border-radius: 7px; box-shadow: 0 10px 30px rgba(0,0,0,0.1); } .task-input{ height: 52px; padding: 0 25px; position: relative; } .task-input img{ top: 50%; position: absolute; transform: translate(17px, -50%); } .task-input input{ height: 100%; width: 100%; outline: none; font-size: 18px; border-radius: 5px; padding: 0 20px 0 53px; border: 1px solid #999; } .task-input input:focus, .task-input input.active{ padding-left: 52px; border: 2px solid #3C87FF; } .task-input input::placeholder{ color: #bfbfbf; } .controls, li{ display: flex; align-items: center; justify-content: space-between; } .controls{ padding: 18px 25px; border-bottom: 1px solid #ccc; } .filters span{ margin: 0 8px; font-size: 17px; color: #444444; cursor: pointer; } .filters span:first-child{ margin-left: 0; } .filters span.active{ color: #3C87FF; } .controls .clear-btn{ border: none; opacity: 0.6; outline: none; color: #fff; cursor: pointer; font-size: 13px; padding: 7px 13px; border-radius: 4px; letter-spacing: 0.3px; pointer-events: none; transition: transform 0.25s ease; background: linear-gradient(135deg, #1798fb 0%, #2D5CFE 100%); } .clear-btn.active{ opacity: 0.9; pointer-events: auto; } .clear-btn:active{ transform: scale(0.93); } .task-box{ margin-top: 20px; margin-right: 5px; padding: 0 20px 10px 25px; } .task-box.overflow{ overflow-y: auto; max-height: 300px; } .task-box::-webkit-scrollbar{ width: 5px; } .task-box::-webkit-scrollbar-track{ background: #f1f1f1; border-radius: 25px; } .task-box::-webkit-scrollbar-thumb{ background: #e6e6e6; border-radius: 25px; } .task-box .task{ list-style: none; font-size: 17px; margin-bottom: 18px; padding-bottom: 16px; align-items: flex-start; border-bottom: 1px solid #ccc; } .task-box .task:last-child{ margin-bottom: 0; border-bottom: 0; padding-bottom: 0; } .task-box .task label{ display: flex; align-items: flex-start; } .task label input{ margin-top: 7px; accent-color: #3C87FF; } .task label p{ user-select: none; margin-left: 12px; word-wrap: break-word; } .task label p.checked{ text-decoration: line-through; } .task-box .settings{ position: relative; } .settings :where(i, li){ cursor: pointer; } .settings .task-menu{ z-index: 10; right: -5px; bottom: -65px; padding: 5px 0; background: #fff; position: absolute; border-radius: 4px; transform: scale(0); transform-origin: top right; box-shadow: 0 0 6px rgba(0,0,0,0.15); transition: transform 0.2s ease; } .task-box .task:last-child .task-menu{ bottom: 0; transform-origin: bottom right; } .task-box .task:first-child .task-menu{ bottom: -65px; transform-origin: top right; } .task-menu.show{ transform: scale(1); } .task-menu li{ height: 25px; font-size: 16px; margin-bottom: 2px; padding: 17px 15px; cursor: pointer; justify-content: flex-start; } .task-menu li:last-child{ margin-bottom: 0; } .settings li:hover{ background: #f5f5f5; } .settings li i{ padding-right: 8px; } @media (max-width: 400px) { body{ padding: 0 10px; } .wrapper { padding: 20px 0; } .filters span{ margin: 0 5px; } .task-input{ padding: 0 20px; } .controls{ padding: 18px 20px; } .task-box{ margin-top: 20px; margin-right: 5px; padding: 0 15px 10px 20px; } .task label input{ margin-top: 4px; } }