An alt file extension are used by Valve Steam program for Windows, Linux and Mac OS X systems.

There are 3 other file types using
the ALT file extension!

alt icon.alt - Corel WordPerfect menu library

empty icon.alt - ReliaSoft ALTA related data

empty icon.alt - Microsoft Dynamics AX temporary data

Detailed description

Software that open alt file

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ALT file extension - Valve Steam data

What is alt file? How to open alt files?

File type specification:

Various data file type icon Various data file type

The alt file extension is associated with the Valve Steam, an application for Microsoft Windows, Apple Mac OS X (macOS) and Linux, which enables users to download and purchase games from Steam service.

The alt file stores game history data used by Steam program.

The default software associated to open alt file:

Steam icon

Valve Corporation logoSteam  Microsoft Windows software

Company or developer:
Valve Corporation

Steam is digital distribution and multiplayer platform. It is used to distribution of computer games, game updates and also has chat and in-game voices features.

Help how to open:

Probably not meant to be accessed by the user.

How to convert:

Probably cannot be converted to anything else.

List of software applications associated to the .alt file extension

Recommended software programs are sorted by OS platform (Windows, macOS, Linux, iOS, Android etc.)
and possible program actions that can be done with the file: like open alt file, edit alt file, convert alt file, view alt file, play alt file etc. (if exist software for corresponding action in's database).

Click on the tab below to simply browse between the application actions, to quickly get a list of recommended software, which is able to perform the specified software action, such as opening, editing or converting alt files.

Programs that can create alt file - Valve Steam data

Programs supporting the exension alt on the main platforms Windows, Mac, Linux or mobile. Click on the link to get more information about listed programs for create alt file action.

Microsoft Windows:

Apple macOS / Mac OS X:


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