I am currently working on a Chrome Extension. However, I have come across an issue. Whenever I change a certain aspect of the HTML on the page, it also changes the URL of that webpage. Essentially, I am trying to highlight certain words, and I do that by putting the words in a span and giving that span a class. Example: "This is a question on stackoverflow." becomes This is a <span class=keyword>question</span> on stackoverflow.

However, this changes the URL. Hence, when I try to click the submit button on this webpage, the webpage reloads and returns me to the same webpage with the original URL. Does anyone know why this is and what can be done?