SGF (Smart Game Format) files are a simple and effective way to store records of two-player board games. File information is saved as plain text, which makes the files very small and easy to handle or store. Game information is stored in a tree-based format - in other words, there is one main linear sequence of moves, with any alternatives that have been entered into the record branching away from that main sequence. These branches may have their own branches and so on.

Because an SGF can contain much information - including but not limited to board setup, markings, variations, and extensive comments - programs such as qGo have been created. qGo provides a powerful, easy-to-use interface for creating, editing and viewing SGF files.

But there are some very old games out on the web in an older format. qGo is able to convert this format to SGF automatically when loading those files.