Why normalise first?
Two systems rarely serialise XML the same way: one indents with tabs, another writes everything on one line, a third reorders attributes. With Format before comparing both documents are parsed and written out identically, so the diff shows only differences in content — a changed amount, a missing element, another schemeID.
Typical Belgian uses: comparing the Peppol invoice your ERP produced with the one your access point delivered, checking two versions of a CAMT export, or reviewing changes between test and production SOAP messages.
Is my data uploaded?
No. The comparison runs in your browser, so nothing you add is sent to gratistools.be. It only leaves your device if you sign in and press Save, which stores that one comparison in your account until you delete it. See the privacy page for details.