Use the checked attribute to specify an <input> element is to be pre-selected on page load. The attribute works with −
<input type = "checkbox"> <input type = "radio">.
Example
You can try to run the following code to implement checked attribute in HTML −
<!DOCTYPE html> <html> <body> <p>Which sports do you like?</p> <form action = "" method = "get"> <input type = "checkbox" name = "vehicle" value = "football" checked> Football<br> <input type = "checkbox" name = "vehicle" value = "cricket" checked> Cricket<br> <input type = "checkbox" name = "vehicle" value = "hockey"> Hockey<br> <input type = "submit" value = "Submit"> </form> </body> </html>