About 7-Zip
7-Zip is an archiving utility created by Igor Pavlov. With it you can gather documents into a single compressed file, open an archive someone has sent you or package a folder ahead of a transfer. From its desktop interface you can view what an archive holds and the options used to build new ones. The tool falls within the category of utilities. This page describes its use on Windows, for which separate installers exist depending on the machine's architecture. Use is free, whether at home or at work. The archiving features ask for neither an account nor paid activation.
The real appeal lies in the control you get while building an archive. You set the format, the compression method, the dictionary size and, where it applies, a password. The 7z format draws on methods such as LZMA and LZMA2. ZIP is a second way to produce archives, whereas RAR is recognized only for extraction. That distinction counts: the formats a program can open are not always the ones it can make.
7-Zip fits folder sharing, gathering project files and archive tasks you repeat often. A command line tool rounds out the graphical interface. How much the size drops depends on your files and the settings you pick. The program makes no promise of an identical reduction for every folder, nor does it repair a damaged file on its own.
Match the format to whoever receives the archive
Before you start creating, think about how the archive will later be opened. A folder you send to someone else need not share the format of a set you keep for yourself alone. The Add to Archive dialog in 7-Zip presents several choices, among them 7z and ZIP. The first opens the door to LZMA, LZMA2 and solid compression. The second suits cases where ZIP is specifically expected. Even so, confirm that the recipient's application handles the compression and encryption methods in use. A correct file extension alone does not prove compatibility. Hold on to your originals until you have checked the result and seen it open properly.
Shield the file names as well as the contents
The password is entered in the settings for creating an archive. For a 7z archive, you can additionally switch on file name encryption. Without it, the list of contents would stay readable even with no password. AES-256 encryption exists for both 7z and ZIP, though their remaining options are not the same. Pick a secret phrase you can store somewhere other than the archive. Then try opening the result with the application meant to read it. Even when protected, the archive does not replace keeping the source documents and reviewing your settings. Keep access to the password somewhere apart from the archive it is supposed to unlock.
Tune compression to the memory you have
The download size says little about the memory each operation calls for. In the creation dialog, dictionary size, method and the other settings shift the resources compression demands. 7-Zip shows estimates for both compressing and decompressing. On a modest machine, begin with cautious settings and look at these figures before you handle a large folder. Heavier compression can draw on more resources without usefully shrinking your particular files. Spare a thought for the computer that will open the archive afterwards too. Free space has to hold either the archive produced or the extracted data, according to the operation underway.
Extract into a folder chosen on purpose
Open the archive first to scan its file list, then name a destination folder that is easy to recognize. The extraction command lets you set that location and decide what happens when files are already there. It helps when you mean to keep several versions of a project apart. Dragging into Windows Explorer can spawn temporary files before the final copy is made. Use 7-Zip's extraction command to skip that intermediate step. If the archive comes in several volumes, gather every part before you begin. Reserve room for the decompressed contents as well, since they may be far heavier than the file you received.
Check an archive before the originals go
The Test command checks that the archive data can be read and may flag errors. Run it after an important archiving job or whenever a download looks incomplete. A result with no errors speaks to the integrity of the archive tested; it is not an antivirus scan of its contents. If a CRC or data error turns up, keep the source files and obtain another copy before you delete anything. A split archive also calls for confirming that every part is present. For important folders, finish by comparing the extracted items against the files you truly meant to collect, which doubles as a check on your selection.
When Total Commander is the better fit
Within the catalog, Total Commander may appeal if most of your work is about moving and organizing files from one folder to another. Its two-panel interface includes archive operations as well. 7-Zip, by contrast, builds its workflow around creating, extracting and the settings that go with them. So weigh your most frequent task first: preparing an encrypted archive and juggling several locations each day call on different tools. The two programs also differ in their licensing terms. Read the Total Commander page to weigh that alternative, without assuming it can create every format offered here. Let your decision follow the work you do most often.
Key features
- Produce archives in the 7z format with LZMA2.
- Bring several files together inside one ZIP archive.
- Unpack the contents of RAR archives you receive.
- Secure 7z and ZIP archives with AES-256 encryption.
- Conceal the file names within an encrypted 7z archive.
- Break an archive into several independent volumes.
- Verify archives to catch possible data errors.
- Launch archive tasks straight from the command line.
System requirements
Windows 11, 10, 8 or 7; x64, x86 and ARM64 installers according to system architecture; minimum RAM and installation space not published; allow room for archives and extracted files.
How to install
- Check the architecture in Windows system information: x64, x86 or ARM64. Select the matching EXE installer.
- Open the downloaded file. If Windows requests administrator permission, check that the request belongs to the installer you just launched.
- In the installer window, keep the proposed destination folder or select another location, then click Install.
- Wait for copying to finish, then click Close. Open 7-Zip File Manager from the Start menu.
