How to Open Split 7z Archives (.7z.001, .7z.002 …)

A file ending in .7z.001 is the first piece of a 7z archive that was cut into several volumes. On its own it is not a complete archive, so opening it alone usually fails. This guide explains how split 7z archives work, how to open them on a computer or phone, and what to do when a part is missing or damaged.

Updated 2026-10-13 · Written and tested by the UnpackNest editorial team (TECCONET)

Step by step: open all parts at once in UnpackNest

1. Put every part (.7z.001, .7z.002 …) in one folder and keep the original names.
2. Open the 7z tool and press Choose a 7z file.
3. In the file picker, select all parts together (Ctrl+A or Cmd+A in that folder, or tap each part on a phone). The order does not matter.
4. If a part is missing, the tool names it. Otherwise it lists the contents of the whole set.
5. Press Extract next to the files you need.

What a split 7z archive is

When 7-Zip creates an archive, it can split the output into volumes of a fixed size, for example 100 MB or 4 GB. Each volume gets the same base name plus a three-digit number: photos.7z.001, photos.7z.002, photos.7z.003 and so on. Every volume except the last has exactly the chosen size; the last one holds whatever is left.

The important detail is that 7-Zip volumes are a plain byte-level split. The tool writes one normal 7z archive and simply cuts the stream into pieces. Part 002 does not contain its own header or file list. That is why no part can be opened independently, and why every part must be present before any file can be extracted. Even a small text file stored at the beginning of the archive may need the end of the last part, because a 7z archive keeps its table of contents at the end.

Why people split archives

• Upload and attachment limits. Email services, forums and some file hosts cap the size of a single file.
• FAT32 drives. USB sticks formatted as FAT32 cannot store a single file larger than 4 GB, so large backups are split into 4 GB volumes.
• Unreliable connections. If one 200 MB part fails to download, you only need to fetch that part again instead of the whole archive.
• Old optical media. Backups that were burned to CDs or DVDs were split to fit each disc.

Split 7z, split ZIP and multi-part RAR are different

Names that look alike can hide different formats, and the right tool depends on which one you have.

If a download only shows .001, .002 without a format name, look at the first bytes of part 001: a 7z archive starts with the characters 7z followed by the bytes BC AF 27 1C. The UnpackNest 7z tool checks this signature for you before it reads anything else.

Before you start: check that the set is complete

1. Put every part in the same folder.
2. Make sure the numbering has no gaps: .001, .002, .003 … up to the last part.
3. Compare sizes. All parts except the last should be identical in size. A part that is smaller than its neighbours, or a file ending in .crdownload, .part or .tmp, is an unfinished download.
4. Check that the base name is the same on every part. Browsers sometimes rename duplicates to photos (1).7z.002, which breaks the set until you rename it back.
5. If the sender published checksums (often an .sha256 file), compare them now. Fixing a broken part later is much harder.

How to open split 7z files in your browser

This works on Windows, macOS, Linux, Chromebooks and phones, and the archive is never uploaded.

1. Open the UnpackNest 7z extractor.
2. Tap Choose a 7z file and select all parts at once. On a computer, hold Ctrl (or Cmd on a Mac) to select several files; on a phone, use the multi-select option of the file picker. The order does not matter.
3. The tool checks that the parts belong to one archive and that none are missing, then lists the contents.
4. Press Extract next to the file you need. 7-Zip verifies its checksum before the file is saved.

If a part is missing, the tool names it, for example “Missing part(s): photos.7z.002”, instead of failing with a vague error. If the archive is password-protected, type the password; it never leaves your device.

How to open split 7z files on Windows

Install 7-Zip from the official site, then right-click name.7z.001 and choose 7-Zip → Open archive or Extract here. 7-Zip finds the other volumes automatically as long as they are in the same folder and keep the same base name. Windows 11 can open many archive formats in File Explorer, but multi-volume sets are handled more reliably by 7-Zip itself.

How to open split 7z files on a Mac

macOS Archive Utility does not handle 7z volumes. Use a free archiver such as Keka or The Unarchiver and open the .7z.001 file with the other parts beside it, or use the browser tool above. In Terminal, if you have installed the 7zz command (for example through Homebrew), run 7zz x name.7z.001.

How to open split 7z files on Linux

Most distributions package 7-Zip as 7zip or p7zip-full. Run 7z x name.7z.001 (or 7zz x name.7z.001) in the folder that contains all parts. Graphical archive managers that use 7-Zip in the background usually accept the .001 file as well.

How to open split 7z files on Android or iPhone

Phones rarely include a 7z extractor. On Android, some file managers and dedicated archive apps support 7z volumes, but quality varies. On iPhone and iPad, the Files app handles ZIP but not 7z. The simplest route on both is the browser: download all parts into one folder, open the 7z tool, select every part and extract only the files you need. Large archives use a lot of memory on a phone, so extracting one file at a time is kinder to the device than extracting everything.

Fixing common errors

“Missing part” or “Unexpected end of archive”

At least one volume is absent or the last part is incomplete. Download the missing part again from the original source. Because the 7z index sits at the end of the archive, an incomplete last part breaks the whole set, not only the last files.

“Cannot open the file as archive”

You probably opened .002 or a later part instead of .001, or the parts were renamed. Always start with part .001. If the first part itself is damaged, the archive cannot be opened at all.

“CRC failed” or “Data error”

One part contains corrupted bytes. The checksum tells you which files are affected, not which part is at fault. If checksums for the parts were published, compare them to find the bad volume and download only that one again.

“Wrong password”

The parts are fine but the password is not. Remember that passwords are case-sensitive, and that copying a password from an email can add a trailing space. Archives created with “encrypt file names” do not show a file list until the right password is entered.

Joining the parts into one file

Because 7z volumes are raw slices, joining them in order produces a normal .7z file. This is useful when an app refuses volumes but opens single archives.

• Windows (Command Prompt): copy /b name.7z.001 + name.7z.002 + name.7z.003 name.7z
• macOS or Linux: cat name.7z.0* > name.7z

The joined file needs as much free space as all parts together, and it is only valid if every part is complete.

Frequently asked questions

Do I need to extract each part separately?

No. Open only the first part (or select all parts in the browser tool). Extracting the parts one by one does not work, because they are pieces of one archive.

Can I recover files if one part is lost for good?

Usually not. Without the missing bytes, 7-Zip cannot rebuild the files that cross that part, and losing the last part also loses the archive index. Files stored entirely in earlier parts can sometimes be salvaged with specialised recovery tools, but there is no guarantee.

Is it safe to open split 7z files from the internet?

Extracting is safe in itself, but the files inside may not be. Scan extracted programs with up-to-date security software before running them. UnpackNest also blocks entries whose paths try to escape the extraction folder.

Why does the browser tool ask me to select all parts at once?

A web page can only read files that you choose. Selecting every part in one go gives the tool access to the whole set, so it can check for gaps and read the archive locally without uploading anything.

Related guides

• 7z vs ZIP vs RAR: Differences, Strengths and When to Use Each
• Why Won’t My RAR File Open? 7 Checks Before You Try Again
• How to Open .tar.gz and .tgz Files on Windows, Mac and Your Phone