Myth Busting about Office document formats


We’ve received some questions from readers in the last few days showing that, even after a decade, there’s still misinformation about the ‘new’ Office document formats .docx .xlsx etc. We’ll explain these myths and how you can easily disprove them yourself.

Most of these myths surround the use of ZIP compression to make the document files smaller.  Folks have jumped to wrong conclusions after hearing about ZIP.

The new documents are NOT just old documents in a ZIP container.  This myth says that .docx  is just a .doc file, compressed with ZIP and renamed .docx.  Bollocks … total bollocks.

The new Office formats are fundamentally different using XML structures before compression.

ZIP files have a password option but it’s very weak and relatively easy to crack.  This has led to the myth that MS Office password protection is also weak.  Again, Bollocks … total bollocks.

The password protection is NOT the zip password lock.  Office encrypts the entire contents to a high level.

Be your own myth buster

Anyone can bust these myths themselves, you don’t need to believe us.

Take a .docx file, rename to .zip then extract the contents to your computer- you’ll be able to see the XML files that make up the document.

Open one of the .xml files (like document.xml) to see how a modern Office document is made.

It looks a little like a HTML web page with <tags> because both new Office documents and HTML are types of XML.

The ZIP password myth is busted in a similar way.  Make a password protected Office document, rename to .ZIP then try to open it.  You can’t!  There’s a ‘corrupt or damaged file’ error because the whole package has been encrypted.


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