Document shredders are a type of paper shredder that destroy papers to prevent important information from being stolen. Documents like bank statements, bills, taxes, private letters and medical records are shred on a daily basis in homes, offices and large institutions and corporations.

There are 3 basic types of document shredders. Personal shredders are small, portable and used in homes or offices. Departmental shredders are large shredders used in larger companies, schools and other settings that produce a moderate to high level of sensitive documents for shredding. Corporate shredders are very large industrial shredders that shred up to 8 thousand pounds of paper in an hour. These large shredders may be fully automated or require hand feeding. Secure document disposal companies often mount industrial shredders on trucks; this guarantees the immediate disposal of documents, under the client's supervision if necessary. Hospitals, banks, law offices, financial institutions, large corporations and government agencies use document shredders to protect against identity theft, fraud and blackmail. These shredders tear papers into very thin strips, small confetti like squares or tiny shreds to ensure that documents are completely unreadable.
Since there are so many different kinds of document shredders for a wide range of consumer needs, they are often classified according to the shape and size of the shreds they produce. Single cut shredders are the least effective, because they merely slice papers vertically into thin strips. Documents shredded in this way are not reassembled easily, though it is possible. Cross-cut shredders' blades cut paper horizontally and vertically, which produces small squares of paper. This process is much more secure than the single cut process, but if spy agencies can make shoe phones, an ambitious corporate or international espionage effort may be able to reassemble documents destroyed in this way. High-security shredders, however, will stymie the craftiest identity thieves and secret snatchers. These machines reduce paper to extremely tiny shreds, making document reassembly impossible. This shredding method is the most expensive, but it provides the greatest security. After document destruction, the left-over shredded paper can be sent to recycling centers. Because most paper recycling operations run paper through a pulper anyway, shredded paper is easily recycled.