howtosimply.com/guides/how-to-open-a-split-zip-file-on-a-mac/ · Checked October 2026 · MacBook Neo · macOS 27.0.1

In this guide

See why double-clicking fails
Put all the parts in one folder
Install Keka, then right-click the .001 and choose Open With, Keka
Find the rebuilt folder
Check nothing is missing
If you do not see this option
If this does not work
Good to know
Sources

Quick answer

The Mac's own Archive Utility couldn't open our split ZIP: it said Error 94 - Bad message. Put all the parts in one folder, install the free Keka from keka.io and open the .001 part with it. The Unarchiver also worked.

5 of 5 steps with real screenshots · 2 official sources below

Device: Mac
Shown on: macOS 27.0.1 (MacBook Neo)
App: Keka
Real screenshots: 5 of 5 steps
Checked: October 2026
Sources: 2 official, linked below

Step by step

Zoomed in on the setting. Tap to see the whole screenTap the picture to see it full size
See why double-clicking fails
Ours said: Unable to expand "A4_split.zip.001" into "x_AU". (Error 94 - Bad message.) Click OK.
Done
Zoomed in on the setting. Tap to see the whole screenTap the picture to see it full size
Put all the parts in one folder
Every part must be there with the same name. Ours: A4_split.zip.001 to .004 at 500 MB and .005 at 97.8 MB.
Done
Zoomed in on the setting. Tap to see the whole screenTap the picture to see it full size
Install Keka, then right-click the .001 and choose Open With, Keka
Keka is free from keka.io. Ours listed The Unarchiver as the default for .001 files, because we had installed it too, with Keka below it.
Done
Zoomed in on the setting. Tap to see the whole screenTap the picture to see it full size
Find the rebuilt folder
Keka puts the folder next to the parts. Ours, big, shows 19:09, the time the folder had when we zipped it, not the time it was rebuilt.
Done
Zoomed in on the setting. Tap to see the whole screenTap the picture to see it full size
Check nothing is missing
Select the folder and press Command + I. Ours said 2.104.432.982 bytes (2,1 GB on disk) for 107 items.
Done

If you do not see this option

Prefer The Unarchiver? It extracted our split archive too, after asking for Desktop access. Its window shows a CleanMyMac Try 7 Days Free banner. Source: open any archive on Mac
Don't want The Unarchiver to send usage data? Ours had analytics on after install. In The Unarchiver's Settings, Analytics, untick Enable analytics; Share my usage statistics then turns grey. Source: open any archive on Mac
Keka not listed under Open With? Choose Other at the bottom of the list and pick Keka in Applications, or open Keka and drop the .001 onto its window. Source: the macOS file archiver
Making a split ZIP with Keka failed? Ours said Error code 2 using 7zz the first time, when we typed a name ending in .zip. With the name A4_split and no extension it worked.

If this does not work

Keka asks where to save? It says it has no file access to the destination folder and needs to ask; you can add folders in Keka's File Access settings. Source: the macOS file archiver
Still fails? Check no part is missing or smaller than the others. Ours had four 500 MB parts and a smaller last one.

About this guide

Our test was a 2 GB folder of photos and videos split by Keka into five parts: A4_split.zip.001 to .004 at 500 MB each and .005 at 97.8 MB. Keka and The Unarchiver both rebuilt the whole folder; Archive Utility failed.

The screenshots are from our MacBook Neo with macOS 27.0.1, Keka 1.6.8 and The Unarchiver 4.3.9, in Dark mode, taken on 25 October 2026, with test archives we made from our own photos and videos.