Get the width of an <object> element:
var x = document.getElementById("myObject").width;
Click the button to display the width of the object element.
<!DOCTYPE html> <html> <body> <object id="myObject" width="250" height="200" data="video.mp4"></object> <button onclick="myFunction()">Test</button> <p id="demo"></p> <script> function myFunction() {// w w w . ja va 2 s. co m var x = document.getElementById("myObject").width; document.getElementById("demo").innerHTML = x; } </script> </body> </html>