# Comparing Document Versions

During a document's complete lifecycle, it may undergo many changes. Vault allows you to compare two versions of a document to see what has changed between them. Note that you must have _View Content_ and _View Document_ permission on both versions.

## How to Compare Document Versions

For documents with more than one version, the _Version History_ section is displayed in the _Documentation Information_ panel. To compare the version you are currently viewing to another version, select **Compare version** from the other version's **Actions** menu in the _Version History_ section.

You can also access this option from the <a href="/en/gr/162/">**Version History** dialog</a>
.

## Comparison Mode

When you compare two versions, Vault opens the document in comparison mode. In this mode, inserted text is highlighted in purple and deleted text is marked with a note.

You can close comparison mode using the **Back to previous page** link.

## Limitations

There are some limitations to document comparison:

  * Vault detects changes to text only. Vault does not detect changes to images, tables, formatting, page additions or removals, or other structural changes.
  * Vault cannot detect changes in text that is not searchable, for example, text in image files.
  * When large portions of a document change, or when a document changes structurally, the number of changes may be so large as to make document comparison unhelpful.
  * When Vault detects more than 5,000 distinct changes between versions, it does not display any changes.
  * Vault does not add a note for text deleted from the end of a document. To see content removed from the end of a document, you must compare a previous version that has the removed text to a newer version that does not have the text. The missing text is considered an addition and is highlighted purple.
  * In rare cases, Vault detects extra spaces that do not exist. This causes unchanged text to be highlighted as changed.
  * Vault may be unable to correctly identify changes between versions when the file formats vary, such as comparing a .DOC file to a .DOCX file or comparing a .CSV file to an .XLSX file.