Rotate Odd or Even PDF Pages Together
In some double-sided scans, every other page is upside down. If your document follows that pattern, selecting the odd or even pages lets you apply one correction to the whole group.
Find the group first
Check a few pages to work out which group the upside-down ones are in. Odd selects pages that run 1, 3, 5; Even selects pages that run 2, 4, 6.
The numbers used here are the order the app shows under the cards. The number printed on the page itself may be different.
Turn the group and save
Once the group is selected, use Rotate 180° in the secondary menu for pages that are upside down. If the pages are on their side, apply a 90° turn with Rotate left or Rotate right. Check the result and save the whole PDF as a new file.
When this does not fit
This approach only fits when the pages to correct really do run odd or even. If other pages are mixed in, use the cards or selection by number instead.
Odd and even selection does not re-pair fronts and backs, reorder anything, or build a booklet layout. It only changes the orientation of the group you selected.
Turn your pages in the browser → Rotate PDF