Chrome Web Inspector: Find and Replace
Taken from this page at labnol.org
While you are on the web page, press Ctrl+Shift+J on Windows or Cmd+Opt+J on Mac to open the Console window inside Chrome Developer tools. Now enter the following commands to replace all occurrences of the word ABC with XYZ.
document.body.innerHTML = document.body.innerHTML.replace(/ABC/g, "XYZ")
document.head.innerHTML = document.head.innerHTML.replace(/ABC/g, "XYZ")
Nothing built in natively. There is a Search and Replace plugin that might help if you want to change text in the input fields.
Alternatively if you want to search and replace in the HTML you could Right Click → Edit as HTML the <body> in the DevTools Elements Panel select all the text with Ctrl+a, paste into your favourite editor, make the change there and paste it back.