I have 7z on windows , and I want to encrypt 1 txt file with AES256 via 7z command line.

How can I do it please?

2 Answers 2


To make the answer simple just use the switch -p which means Set Password with the default encryption which is AES.

The example below will encrypt the file or folder and prompt for a password:

  • 7z a -p Zip_File_Name File_2_zip.txt

The following example will auto add the password to the file for you.

  • 7z a -pPassword Zip_File_Name.7z File_2_Zip.txt

The other switches used above are:

7z a -p -mhe=on Zip_File_Name.7z File_2_Zip.txt

 -pPassword   ==  Auto add password without being prompted
 -mhe=on      ==  Means to encrypt the file names in archive too.

Any time you use the .7z format, the file is AES-256 encrypted.

Arguments explained:

-pPASSWORD: setting the password PASSWORD.
u: update existing archive with new or modified files.
-mx: default compression level (5/6) - -mx1 (fastest) to -mx9.
-mhe: encryption of file headers (encrypted file names).

  • Can you please explain me what is the arguments u and mx and mhe ? Thank you Nov 22, 2018 at 4:14
  • 1
    One issue per question, please, as per house rules. dotnetperls.com/7-zip-examples offers details.
    – K7AAY
    Nov 22, 2018 at 23:28
  • 2
    Is it documented somewhere? I can see that the -mem switch (EncryptionMethodID) is available for zip type. Documented here: sevenzip.osdn.jp/chm/cmdline/switches/method.htm - but the documentation does not say anything about the cipher used for other types. So how do you know?
    – nagylzs
    Nov 13, 2019 at 17:16
  • 2
    Asking what your answer means is not against the "house rules"! If anything, giving a literal answer to the question without any explaination is against them. Sep 18, 2020 at 20:14

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