To set the indentation, use the textIndent property.
Example
You can try to run the following code to return the indentation of the first line of text with JavaScript −
<!DOCTYPE html> <html> <body> <div id = "myText"> This is demo text. This is demo text. This is demo text. This is demo text. This is demo text. This is demo text. </div> <br> <button onclick = "display()">Set Text Indent</button> <script> function display() { document.getElementById("myText").style.textIndent = "50px"; } </script> </body> </html>