Getting the PDF
In American Express online banking, statements are usually under Statements & Activity. Download the PDF itself; a screenshot or a scan will not work.
What the tool reads in a American Express statement
Card statements with the closing date and billing-cycle days instead of a date range, posting-date markers, travel charges followed by arrival and departure date lines, and balances repeated for each portion of the account; the Account Total block is the one that ties out.
Before comparing anything, the tool adds the lines it read to the beginning balance and checks the result against the ending balance printed on the statement. If they disagree it says so, instead of guessing.
Files are read inside your browser tab. Nothing is uploaded, no account is needed, and nothing is saved: closing the tab clears everything. The processing code is open source.
nildiff is independent and is not affiliated with or endorsed by American Express. Bank names are used only to describe statement layouts.