NZB is a file format for storing information about Usenet posts containing the files. The worldwide distributed discussion forum Usenet is among other things used for the offering and downloading files. The part of the Usenet, which is used, in principle, only to also called Binary Usenet, because of the binary ( " binaries "), which can be found there, unlike in other text-based Usenet. Since size limits for individual Usenet posts exist, files are divided into several individual posts from a certain size. An NZB file contains references to all individual contributions that are required to decode the file, making it a kind of index.

NZB search engine

Special search engines allow you to locate files by their name or other properties such as the file type or size in bytes. For found matching files then download a NZB file for this file is offered. Certain newsreaders can thus be selectively download the posts and put together the file on the local machine.

By using such search engines and NZB files, the user avoids the time-consuming and bandwidth- consuming downloading all the headers of newsgroups to which for him are thematically interesting. Instead happens to find interesting files on the search engine and then only needs to download the relatively compact NZB file.

Some service providers offer equal to the decoded binary files via HTTP download all modern conveniences, so that the user no longer comes into contact with Usenet specific programs.


NZB files are implemented as an XML dialect.

In a NZB file, the Message-ID values ​​of all necessary contributions for a file to be stored. In addition, the newsgroups are called, in which these contributions have been sent, the author's name and the date and time it is sent.

NZB files are generated by programs that have access to newsgroups and search in these regularly new posts on file attachments.


NCB was originally defined by the operators of the website The term NCB is an abbreviation for Newzbin.