WordPress automatically saves changes and preserves old drafts of every page. If you would like to revert a page back to how it was formatted before, you can:

  1. Go to the page and open the editor
  2. Go to Document Settings in the upper right hand corner
  3. Click Revisions
Page settings with the Revisions section bring highlighted.
  1. Select the appropriate version by dragging the arrow at the top of the page and click “Restore This Version”
Revisons page in the editor.