Steam Client temporary data
File type: Temporary file
A .steamstart file is temporary data created by the Steam Client, Valve's game distribution and management software.
It is associated with starting games installed through Steam and is not intended as a user-openable document.
File type category:
Temporary file
Date updated: October 12, 2026
The steamstart file extension is associated with Steam, the game client developed by Valve. When a game installed through Steam is launched, the client creates a temporary .steamstart file for digital rights management (DRM) or other internal purposes.
This file is part of Steam's temporary operating data rather than a game save, installation package, or general-purpose document. Steam is available for Microsoft Windows, Apple macOS, and Linux/Unix systems. The format is intended for Steam's internal use and is not designed for independent use outside the client.
.steamstart files are not meant to be opened directly. They are generated by the Steam Client for temporary internal purposes when a Steam game is launched.
Steam on Microsoft Windows, Apple macOS, and Linux/Unix handles these files automatically. There is no need to open them with a separate program.
A .steamstart file cannot be meaningfully converted to another format. It contains temporary Steam Client data for internal DRM or startup purposes, not content intended for export or reuse.
Software apps that create steamstart files:
Software applications that handle other tasks involving steamstart files:
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