What is on my Punch Card?
The Punch Card Sampler

This is a simple tool for detecting data on a punch card: reproduce the punch holes on your card column by column by clicking on the sample below and learn what’s on your card.
Choose an appropriate character set / encoding from the pop-up menu by an elaborate guess.

Disclaimer: Data may be subject to error and is provided without warranty, express or implied, and excluding all liability.

column:   row:

Click card to add/remove punches.

... square lozenge (subtotal, second level total)
... substitute blank (“b” slashed)
... record mark (two horizontal lines crossed by a bar)
... group mark (three horitontal lines crossed by a bar)
... segment mark (three vertical bars crossed by a horizontal line)
... tape mark (square root sign)
Δ ... mode change (Greek letter capital delta)
? ... unknown code

Characters with grey background are non-printable and show their respective meaning in a tooltip.
Columns 73–80 commonly hold a card identification used for sorting.