7Z file icon

7Z File Extension

7-Zip Compressed Format

What is 7Z file?

Files with the .7Z extension contain archived data, which can be compressed and encrypted. It enables to use pre-processing algorithms - BCJ, BCJ2 and Delta Encoding. An archive can be divided, and in such situation extensions of specific elements of a package are complex: name.7z.001, name.7z.002, etc.. This format provides high level of compression and it is open, therefore – various algorithms can be used for data compressing.

The most popular algorithms used for compression in 7Z format:


  • LZMA – base on LZ77 algorithm, but providing better parameters,
  • LZMA2 - upgraded LZMA,
  • PPMD – algorithm based on PPMdH, introducing some small changes,
  • BZip2 - classic BWT algorithm,
  • Deflate – classic, based on LZ77 algorithm.

7Z is native for the 7-Zip program, it uses the LZ77 compression algorithm as default. It supports AES-256 encryption, using derivative functions based on the SHA-256 algorithm in order to create a key based on the password provided by the user. Format was developed in 1999 by Igor Pavlov.

Programs which support 7Z file extension

The following list contains programs grouped by 3 operating systems that support 7Z files. 7Z files can be encountered on all system platforms, including mobile, yet there is no guarantee each will properly support such files.

Updated: 07/18/2023

How to open file with 7Z extension?

Problems with accessing 7Z may be due to various reasons. Fortunately, most common problems with 7Z files can be solved without in-depth IT knowledge, and most importantly, in a matter of minutes. The list below will guide you through the process of addressing the encountered problem.

Step 1. Download and install 7-Zip

Install software to open 7Z file Problems with opening and working with 7Z files are most probably having to do with no proper software compatible with 7Z files being present on your machine. The most obvious solution is to download and install 7-Zip or one to the listed programs: WinZip, B1 Free Archiver, StuffIt Deluxe. Above you will find a complete listing of programs that support 7Z files, classified according to system platforms for which they are available. If you want to download 7-Zip installer in the most secured manner, we suggest you visit Igor Pavlov website and download from their official repositories.

Step 2. Verify the you have the latest version of 7-Zip

Update software that support file extension 7ZIf the problems with opening 7Z files still occur even after installing 7-Zip, it is possible that you have an outdated version of the software. Check the developer’s website whether a newer version of 7-Zip is available. Sometimes software developers introduce new formats in place of that already supports along with newer versions of their applications. The reason that 7-Zip cannot handle files with 7Z may be that the software is outdated. The latest version of 7-Zip should support all file formats that where compatible with older versions of the software.

Step 3. Assign 7-Zip to 7Z files

If the issue has not been solved in the previous step, you should associate 7Z files with latest version of 7-Zip you have installed on your device. The next step should pose no problems. The procedure is straightforward and largely system-independent

Associate software with 7Z file on Windows

Change the default application in Windows

  • Right-click the 7Z file and choose Open with option
  • Click Choose another app and then select More apps option
  • The last step is to select Look for another app on this PC option supply the directory path to the folder where 7-Zip is installed. Now all that is left is to confirm your choice by selecting Always use this app to open 7Z files and clicking OK.
Associate software with 7Z file on Mac

Change the default application in Mac OS

  • From the drop-down menu, accessed by clicking the file with 7Z extension, select Information
  • Open the Open with section by clicking its name
  • Select the appropriate software and save your settings by clicking Change all
  • If you followed the previous steps a message should appear: This change will be applied to all files with 7Z extension. Next, click the Continue button to finalize the process.

Step 4. Verify that the 7Z is not faulty

If you followed the instructions form the previous steps yet the issue is still not solved, you should verify the 7Z file in question. Being unable to access the file can be related to various issues.

Check 7Z file for viruses
1. Check the 7Z file for viruses or malware

If the file is infected, the malware that resides in the 7Z file hinders attempts to open it. It is advised to scan the system for viruses and malware as soon as possible or use an online antivirus scanner. If the 7Z file is indeed infected follow the instructions below.

2. Check whether the file is corrupted or damaged

If you obtained the problematic 7Z file from a third party, ask them to supply you with another copy. It is possible that the file has not been properly copied to a data storage and is incomplete and therefore cannot be opened. If the 7Z file has been downloaded from the internet only partially, try to redownload it.

3. Ensure that you have appropriate access rights

Sometimes in order to access files user need to have administrative privileges. Log out of your current account and log in to an account with sufficient access privileges. Then open the 7-Zip Compressed Format file.

4. Make sure that the system has sufficient resources to run 7-Zip

The operating systems may note enough free resources to run the application that support 7Z files. Close all running programs and try opening the 7Z file.

5. Verify that your operating system and drivers are up to date

Up-to-date system and drivers not only makes your computer more secure, but also may solve problems with 7-Zip Compressed Format file. It is possible that one of the available system or driver updates may solve the problems with 7Z files affecting older versions of given software.

Do you want to help?

If you have additional information about the 7Z file, we will be grateful if you share it with our users. To do this, use the form here and send us your information on 7Z file.

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