https://docs.microsoft.com/windows-server/administration/windows-commands/assoc

assoc

By robinharwood

Archived: 2026-10-18 02:15:44 UTC

Displays or modifies file name extension associations. If used without parameters, assoc displays a list of all the

current file name extension associations.

Note

This command is only supported within cmd.exe and is not available from PowerShell. Though you can use  cmd

/c assoc  as a workaround.

assoc [<.[ext]>[=[<filetype>]]]

Note

In the syntax, square brackets  [ ]  indicate optional items and angle brackets  < >  indicate placeholder values

that you replace with your own text. Don't type the brackets. For example, to remove the association for the .jar

file name extension, type  assoc .jar= , not  assoc .jar=<filetype> . If you type the angle brackets, cmd.exe

treats  <  and  >  as redirection operators and returns an error. For more information, see Command-Line Syntax

Key.

Parameter Description

<.ext> Specifies the file name extension.

<filetype> Specifies the file type to associate with the specified file name extension.

/? Displays help at the command prompt.

To make changes in associations, you need administrator privileges.

To remove the file type association for a file name extension, type the extension and an equal sign with

nothing after it, for example  assoc .ext= . You don't need to add a trailing space after the equal sign.

To associate files without extension to a file type, use just a dot (see the examples).

To view current file types that have open command strings defined, use the ftype command.

To redirect the output of assoc to a text file, use the  >  redirection operator.

To view the current file type association for the file name extension .txt, type:

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https://docs.microsoft.com/windows-server/administration/windows-commands/assoc

assoc .txt

To remove the file type association for the file name extension .bak, type:

assoc .bak=

Type nothing after the equal sign. Don't type placeholder text such as  <filetype> , and don't add a trailing space.

To remove the file type association for the file name extension .jar, type:

assoc .jar=

To view the output of assoc one screen at a time, type:

assoc | more

To send the output of assoc to the file assoc.txt, type:

assoc>assoc.txt

Associate .log to text files:

assoc .log=txtfile

Associate files with no extension to text files:

assoc .=txtfile

Command-Line Syntax Key

ftype command

Source: https://docs.microsoft.com/windows-server/administration/windows-commands/assoc

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