How Do I Check My Google Takeout Export Is Complete?
What to verify before deleting anything from Google, and the counts that matter.
Compare counts. Google Photos shows roughly how many items you have. Count the photos and videos in your extracted export and see whether the numbers are close. A large gap means a part is missing.
Takeout splits big libraries across several zip files, and it is easy to miss one, especially if a download failed quietly. Every part has to be extracted into the same folder, or photos will be absent and sidecars orphaned.
Delete nothing from Google until the export is extracted, counted and fixed, and you have opened some photos to confirm they look right. Takeout JSON Metadata Fixer reports how many files it processed and how many it could not date.