HTML Events

Learn how to handle user interactions with HTML event attributes

⚡ What are HTML Events?

HTML events are actions that happen to HTML elements, such as clicking a button, loading a page, or moving the mouse. You can respond to these events using JavaScript.


<!-- Basic event example -->
<button onclick="alert('Hello World!')">Click Me</button>

<!-- Multiple events -->
<div onmouseover="this.style.color='red'" 
     onmouseout="this.style.color='black'">
  Hover over me!
</div>
                                    

Mouse Events

👆

onclick

Triggered when element is clicked

<button onclick="alert('Clicked!')">
  Click Me
</button>
🖱️

onmouseover

Triggered when mouse enters element

<div onmouseover="this.style.background='yellow'">
  Hover me
</div>
🖱️

onmouseout

Triggered when mouse leaves element

<div onmouseout="this.style.background='white'">
  Leave me
</div>
👆

ondblclick

Triggered on double-click

<p ondblclick="alert('Double clicked!')">
  Double click me
</p>

🔹 Keyboard Events

Events triggered by keyboard interactions:

<!-- Key press events -->
<input type="text" 
       onkeydown="console.log('Key pressed down')"
       onkeyup="console.log('Key released')"
       onkeypress="console.log('Key pressed')"
       placeholder="Type something">

<!-- Specific key detection -->
<input type="text" 
       onkeyup="if(event.key==='Enter') alert('Enter pressed!')"
       placeholder="Press Enter">

Output:


🔹 Form Events

Events related to form elements and submission:

<form onsubmit="alert('Form submitted!'); return false;">
  
  <!-- Focus events -->
  <input type="text" 
         onfocus="this.style.background='lightblue'"
         onblur="this.style.background='white'"
         placeholder="Focus me">
  
  <!-- Change event -->
  <select onchange="alert('Selection changed to: ' + this.value)">
    <option value="">Choose...</option>
    <option value="option1">Option 1</option>
    <option value="option2">Option 2</option>
  </select>
  
  <button type="submit">Submit</button>
</form>

Output:



🔹 Window Events

Events that occur on the window or document level:

<!-- Page load events -->
<body onload="alert('Page loaded!')">

<!-- Window resize -->
<body onresize="console.log('Window resized')">

<!-- Before page unload -->
<body onbeforeunload="return 'Are you sure you want to leave?'">

<!-- Scroll event -->
<body onscroll="console.log('Page scrolled')">

<!-- Image load event -->
<img src="image.jpg" onload="alert('Image loaded')" onerror="alert('Image failed to load')">

Output:

These events trigger automatically based on user actions:

  • onload: When page finishes loading
  • onresize: When window is resized
  • onbeforeunload: Before leaving page
  • onscroll: When page is scrolled

🧠 Test Your Knowledge

Which event is triggered when a user clicks on an element?