Work with the complete extracted export
Download and extract all export parts into a stable local location. Check the export’s selected products and albums. A folder comparison cannot discover a photo that was never included in the source export, even if the cloud library contains it.
Select comparable source and destination folders. Takeout sidecars are files too: this tool hashes them, and optionally reads recognized small source JSON files. A sidecar absent from a destination that stores metadata in its own database is a file difference, not proof that the photo itself disappeared.
Treat a sidecar as supporting evidence
Recognized sidecars have a title and photoTakenTime object. The checker considers both the JSON sibling name and the declared title within that same folder. If they point to different selected files, the association remains ambiguous.
A unique sibling association can help you identify a file and a reported capture time. It does not verify that a destination imported the date, description or album membership. Truncated names, repeated names and unusual export layouts can prevent a reliable association; the checker does not invent one.
Check destination-specific transfer limits
Apple documents that some unsupported Google-to-iCloud files may be placed in iCloud Drive, while certain content types are outside the transfer. Inspect the official transfer status and both relevant import locations before declaring a missing asset.
For transfers in the other direction, Google documents exclusions and deduplication. Read the current source notes for the route you actually used. A local byte receipt complements those rules; it does not override a platform’s export behavior.
Resolve differences in a safe order
First retry unreadable files from a stable local copy. Next investigate same-path changes and possible converted versions among extra files. Finally inspect missing rows against the original cloud library, export settings and any additional download parts.
Keep the source export intact while you repeat a destination export with matching original-file settings. Do not delete the source based solely on a green count or one successful sample image.