A document feeder which can be coupled to a motorized, portable optical scanner to feed documents across the scanner window of the scanner, including a housing with a support surface and an opposite offset platform surface which together form a slit through which the document is fed and including openings in the support surface for a drive and a drive set of spring-loaded rollers which are coupled together by a belt, and which extend partially below the platform surface and are adapted to cooperate with drive roller(s) of the motorized, portable optical scanner to feed documents across the scanner.