How to Open Multi-Part RAR and Split ZIP Archives
A sender who splits an archive is trying to get past a size limit on mail or on an old forum. You receive several files that look related and none of them open alone. The names tell you whether you have a multi-part RAR, an old RAR volume set, or a split ZIP, and only one of those shapes can be opened by picking a single file.
Updated 2026-10-22 · Written and tested by the UnpackNest editorial team (TECCONET)
Three different naming schemes
People say "split archive" for all of them. The bytes are not interchangeable.
| What you were sent | What it is | Which file is the start |
|---|---|---|
| report.part1.rar, report.part2.rar, report.part3.rar | Modern multi-volume RAR | part1. Every later part is a continuation |
| report.rar, report.r00, report.r01 | Older RAR volumes | The .rar file is the first volume. .r00 is the second, not the first |
| report.z01, report.z02, report.zip | Split ZIP | The .zip file holds the directory. The .z01 file is not a ZIP you can open alone |
| report.7z.001, report.7z.002 | Split 7z | A different format. Use the 7z guide for .7z.001 sets |
Keep every part in one folder and do not rename them to "help". Changing part2 into part1 does not make it the first volume. It makes the set unreadable.
A short download is not a multi-part set
If you were promised one file and the download is smaller than the sender's number, you have truncation, not volumes. Truncation looks like "unexpected end of archive" or a RAR that fails its header. There will not be a sibling named part2. Repair talk belongs in the corrupted-archive guide. Volume talk belongs here, and only when the other parts are actually on disk.
Count the parts before you start. A set that jumps from part1 to part3 is incomplete. No reader can invent part2. Ask for the missing file, quoting the exact name.
Why the browser RAR page stops
The RAR tool opens one complete RAR4 or RAR5 file. A volume is not complete. Feeding it part1 produces an error about a multi-volume archive, which is accurate, not a bug in the file picker. The page will not ask you to select part2 beside it, because joining RAR volumes needs the whole set and a reader that understands the volume chain. Do not keep retrying part1.
Split ZIP is a similar trap on the ZIP tool. That page expects one .zip whose central directory is intact. A .z01 file has no directory. Opening it reports that the file is not a usable ZIP. Opening the companion .zip while .z01 is missing fails for the same reason: the directory points at data that is not in the file.
Open a multi-part RAR on a computer
Put every volume in a single folder. Install a reader you already trust, such as 7-Zip or the official WinRAR trial for this one job. Then:
- Open the first volume only. For modern names that is .part1.rar. For old names that is the file that ends in .rar, sitting next to .r00.
- Extract to an empty folder. The reader will ask for the next volume if it cannot see it. If it asks, you renamed something or left a part in Downloads.
- If a password dialog appears on volume 1, the set is encrypted. You need the password from the sender. A wrong password across all volumes is still a wrong password, not a missing part.
- Leave the volumes in place until the extracted files open. Deleting part3 because "the extract finished" can hide a file that was stored only in that volume.
On macOS, The Unarchiver and Keka follow the same rule: open the first volume, keep the others beside it. On Linux, unar archive.part1.rar or 7-Zip's 7zz x archive.part1.rar will walk the set if the names are untouched.
Open a split ZIP
- Confirm that report.zip, report.z01 and any further .z02, .z03 files share one folder and one base name.
- Open report.zip, not report.z01, in 7-Zip or WinRAR.
- Extract. The program reads the later volumes by name.
- If you only have the .zip and not the .z01, stop. The directory might list the files and still be unable to inflate them. That is a missing volume, not a CRC you can rebuild.
The browser ZIP tool is the right place once someone has merged the set back into one ordinary ZIP. Merging is a desktop job: 7-Zip's "open the .zip" extract does it by reading the parts, and you can then zip the result again if a phone user needs a single file. Do not concatenate .z01 and .zip with a text editor. ZIP is not a stream you can glue together by hand.
Checksums and "the last part is tiny"
The last volume is often smaller. That is normal. The sender filled each part to a mail limit and left the remainder in the final file. A last part of a few kilobytes can still be legitimate. A last part that is an HTML page, if you open it in a text editor and see <html>, is an error document with the wrong name. Compare sizes with the note the sender sent.
Some sets ship with a separate .sfv or .par2. An SFV checks that each part arrived intact. PAR2 can rebuild a damaged part if the recovery data is large enough. Those are optional. Most mail splits have neither, and then a damaged part means asking for that part again.
Passing a set to someone on a phone
Phones are bad at volume sets. If you are the sender, prefer one ZIP under the mail limit, or a shared drive link to one file, instead of part1 through part6. If you must split, say in the message which file to open first and list every name. Recipients who save only the first attachment will write to you that "the RAR is corrupt".
If you already received a set and only the phone is available, copy the entire folder to a computer with a cable or with a cloud drive that preserves names. Extract there. Send yourself the one document you needed. That detour is faster than cycling the same part1 through the browser.
Safety
Volume sets are a favourite way to hide a program, because each part looks incomplete to a scanner. Extract only if you expect the archive, and open documents rather than installers. The safety guide covers the social tricks (password in the same email, urgency, a double extension). A complete set is not automatically a safe set.
Frequently asked questions
I opened part2 by mistake and it asked for part1
That is the reader working. Close it and open part1, with part2 still in the same folder. You do not extract part2 as its own archive.
The names are part01 and part02 with an extra zero
Keep them. The width of the number is part of the pattern the reader expects. Renaming part01 to part1 can break the chain.
Can UnpackNest join RAR parts if I select them all?
No. The RAR page is one file in, one archive out. Split 7z is the format the 7z page does accept as several files at once, and only with .7z.001 style names.
The first part opens, then extraction stops at 95 percent
A later volume is missing, renamed, or truncated. Check the folder for every index the reader mentioned. Download that one part again. Do not run a repair on the whole set until the missing file is ruled out.
Tools for this task
- Open and extract RAR files in your browserRAR4 and RAR5, read on your device.
- Open and extract ZIP files in your browserStore, Deflate and ZIP64, read on your device.