Short answer: clean up WhatsApp videos on iPhone in two passes. First remove the heavy chat videos inside WhatsApp, then check Photos for saved copies. If you skip the second pass, the same clips can keep taking storage even after the chat cleanup feels done.
This version of the problem is less about general WhatsApp storage and more about duplicate video weight. Forwarded clips, auto-saved videos, and manually saved copies often create the feeling that you deleted something but somehow did not get the space back.
What to clean first
Open the heaviest WhatsApp chats and remove outdated or low-value videos first.
Check Photos for the same clips if auto-save or manual saves were used.
Treat saved camera-roll copies as a second cleanup job, not as part of the chat pass.
Empty Recently Deleted if you need the space back immediately.
Why saved copies keep the phone full
One clip can exist in WhatsApp and in Photos at the same time.
Forwarded or re-downloaded videos can create more than one local copy.
Heavy chat media often overlaps with the normal large-videos cleanup problem.
When to widen into broader video cleanup
If WhatsApp videos are only one part of a larger heavy-media problem, the next move is not another chat pass. It is a broader large-videos review across the whole photo library.
If that broader problem is already clear, open large videos. If you want the WhatsApp-wide route first, continue to How to Clean Up WhatsApp Storage on iPhone.
Safe WhatsApp video cleanup means clearing the chat copy and the saved copy, not assuming they are the same file.