Getting the PDF
In Citi online banking, statements are usually under Statements, on the account page. Download the PDF itself; a screenshot or a scan will not work.
What the tool reads in a Citi statement
Debits, Credits and Balance columns with the balance on every line, and statement periods written like "Oct 1 - Oct 31".
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 Citi. Bank names are used only to describe statement layouts.