When you click "Download my data" on Google Takeout, Facebook, or Spotify, you get a zip with anywhere from a few hundred to tens of thousands of files: nested JSON, HTML, CSV, and media, named after internal product codenames, with no index and no summary. Export X-Ray reads that archive in your browser and answers the first question you actually have: what is in here, and how much of it is there?
Drop the zip on the panel above and Export X-Ray detects which service produced it, then shows the headline numbers as it parses: the total time span the data covers, record counts per category (location points, photos, messages, plays, and so on), the oldest and newest items found, and which of that service's expected categories are present, thin, or missing. It is built for the moment right after you request an export, when you are deciding whether to keep it, migrate it, or delete the account it came from.
Everything runs client-side. There is no upload endpoint, no account, and no analytics. You can open your browser's network tab while using it and watch it make zero requests with your data, and an automated test in the repo fails the build if a future change ever tries.