Internal Steam client data file for application, game metadata, or installation state
File type: Game file
SDFDATA files are internal data files associated with the Steam application from Valve. They may contain application metadata, installation information, or other client-managed data used by Steam.
These files are normally created and read automatically by Steam and are not intended to be opened as documents. The Steam client is the appropriate software for handling them.
File type category:
Game file
Date updated: September 19, 2026
The exact structure and purpose of an .sdfdata file can depend on the Steam component that created it. Steam uses several internal file types to maintain information about games, applications, downloads, and the local client environment.
Such files may use a proprietary or partially undocumented format rather than a standard text, database, or media format. Opening one in a text editor may display unreadable data and changing its contents can interfere with Steam or with the associated game.
Steam generally creates, updates, and removes these files automatically. They can occur in Steam installation or user-data directories on systems running Windows, macOS, or Linux.
Because the format is intended for internal use, there is no broadly supported third-party editor or universal viewer. If a file appears after a Steam update, game installation, or library operation, it is usually best left in its original location.
To handle an .sdfdata file, start or restart the Steam desktop client and allow it to manage the file automatically. Steam is available for Windows, macOS, and Linux.
There is generally no need to open the file directly. Do not rename, delete, or edit it unless Steam support or a trusted troubleshooting guide specifically instructs you to do so. A plain-text editor may open the file as raw data, but it is unlikely to provide useful or reliable information.
.sdfdata files are not normally converted because they store internal Steam data rather than user documents. No standard online converter or general-purpose desktop conversion utility is available for this format.
If the goal is to move or preserve the information, use Steam features such as game backups, library migration, synchronization, or account-based cloud storage where supported. Keep the original file unchanged instead of uploading it to an online conversion service.
Software applications that handle other tasks involving sdfdata files:
Microsoft Windows
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