On a site homepage, the title of the actual site is automatically displayed at the top of the page. For other wiki page library pages (like pages in the Site Pages library) the name of the page will be displayed at the top. We can change the title displayed at the top of the page while leaving the page name and URL the same by inserting a Script Editor Web Part with a one line script.
In the example below we will be changing the page title from ‘MyNewPage’ to ‘New Page Title’.
1. Go to the page, click on the Edit icon in the top right ribbon, click at the bottom of the page (this is where the Script Editor Webpart will be inserted).
2. Click on the Insert tab in the ribbon, click on the Web Part icon.
3. Select the Media and Content category, click on the Script Editor option, click the Add button.
4. The Script Editor should have been added to your page, hover over the web part, click the web part dropdown arrow, select Edit Web Part from the popup menu.
5. You should now see a Edit Snippet option on the webpart, click it.
6. Paste in the following script to the Script Editor webpart, replacing New Page Title with whatever you want your page title to be. After pasting the script, click the Insert button.
document.getElementById(“DeltaPlaceHolderPageTitleInTitleArea”).innerHTML=”New Page Title”;
7. Click the OK button to save the entered Script.
8. Save the page, the title of the page should now be whatever you entered in the script. Also the Script Editor webpart is automatically only visible when editing the page.