Frequently Asked Questions

This topic holds the answers to common questions that are asked about Merge for Windows. If you have a question that should be in this FAQ, please contact Araxis.

Before you purchase

What are the system requirements for Merge for Windows?

Please see the Release Notes & System Requirements (Windows) for this information.

What is the difference between the Standard and Professional Editions of Merge?

Please see Feature Summary and Differences Between Editions for this information.

Does Araxis offer floating (network) licences for Merge?

Araxis does not currently offer network (floating) licences or site licences for Merge, although we are aware of strong demand and will consider offering network licences in the future.

Please note that quantity discounts are available for the Professional Edition of Merge.

Please see the End-User Licence Agreement for Araxis Merge Software for full terms and conditions.

How many licences do I need to buy?

A licence must be purchased for each machine where the product is to be used. The only exception to this is that the primary user of a computer for which a licence has been purchased may make a second copy for his or her exclusive use on a second computer. This means that you can buy a single Merge licence and then use it simultaneously on both a Windows PC and a Mac, provided you are the only person using that licence.

Please see the End-User Licence Agreement for Araxis Merge Software for full terms and conditions.

If I buy new serial numbers, will they work with both Merge for macOS and Merge for Windows?

Yes. See also ‘How many licences do I need to buy?’

If I buy new serial numbers, will they work with earlier versions of Merge as well as the current version?

Yes. Newly-purchased serial numbers will work with versions of Merge back to and including Merge 2012.4246, as well the current version of Merge.

How does support renewal work?

Please see Understanding Serial Numbers, Support Expiry & Upgrade/Support Entitlement and Buy Araxis Merge.

Is there a version of Merge for Linux?

Unfortunately, no. Customers at one time reported that Merge would run under Wine on Linux. This sadly no longer appears to be the case. We should be grateful to hear from customers that are able to run Merge successfully under Wine.

Another possibility is to run Merge and Windows under Linux using a virtual machine environment such as VirtualBox or VMware Workstation.


Should I uninstall an older version of Merge before installing a newer version or build?

Please see Upgrading From an Older Version of Merge for information about this.

I’ve upgraded from Standard to Professional. How do I enter my new serial number?

For Merge 2020 and later:

Click the Re-register… button in the Application menu About Araxis Merge… window to re-enter registration information.

For Merge 2019 or earlier:

Click the Re-Register… button in the FileAbout Araxis Merge… window to re-enter registration information.

I’m having problems installing Merge, what should I do?

Please see Troubleshooting Installation for solutions to most installation problems.

How do I find out the version and build number of my Merge installation?

For Merge 2020 and later:

The version and build number are available in the Application menu About Araxis Merge… window.

For Merge 2019 or earlier:

The version and build number are available in the FileAbout Araxis Merge… window.

Using Merge effectively

Can I use Merge to compare Microsoft Word or other application documents?

Merge comes with filters for opening and comparing the text content of several popular file formats, including Word documents. See Comparing Text Files (or Typed/Pasted Text) for more details.

Alternatively, you can copy and paste any text from other applications into a Merge file comparison window. So, simply open a new two-way file comparison, then copy the text from one document (in Microsoft Word, press Ctrl+A to select the entire document, followed by Ctrl+C to copy it to the clipboard) and paste it into the left file pane (click in the pane, then press Ctrl+V to paste). Then, repeat, pasting the text of the second document revision that you wish to compare into the right file pane. The differences between the documents will then be shown. This is an effective way to compare, for example, different drafts of a contract being edited with Microsoft Word.

A further possibility for some application formats not supported by Merge (e.g. Microsoft PowerPoint .pptx files) is to open them in their native applications and save them to a different, supported format (e.g. .ppt).

Which version control (VC) or software configuration management (SCM) systems work with Merge?

Please see Integrating with Source Control, Configuration Management, and Other Applications for the latest information.

If you are the developer of a VC or SCM system, Araxis would be pleased to assist you integrate Merge with your product. Please email for further information.

What is the recommended way to use three-way file merging?

Please see Three-Way File Comparison and Merging and Automatic File Merging for this information.

How can I review all the changes I have made before saving?

It is sometimes useful to be able to review all the changes you have made before saving. If you have the Professional Edition of Merge, you can do this for two-way comparisons using the three-way comparison capability.

Open the file that you will be merging from into the left pane and the file that you will be merging into in both the middle and right panes. Whenever something is merged from the left file into the middle one, or if any other change is made to the middle file, the right pane shows exactly what the changes were. This enables you to review all the merges and changes you have made before saving.

How do I make the folder comparison show just added and deleted files?

Use the Hide/revealVisibility filters… ribbon item to choose exactly which files and folders you wish to see.

Is it possible to compare files from different rows in a folder comparison?

Yes. Please see the Launching multiple file comparisons and Launching a file comparison for arbitrary files sections of the Launching File Comparisons topic.

How do I type a tab character in the Merge in-place editor?

By default, pressing Tab on its own moves you between the various panes in Merge file comparison windows. Use Ctrl+T if you want to insert a tab character into the file you are editing.

You can change this behaviour on the Text ComparisonsEditing options page.

How do I create a permanent record of comparison results?

Merge provides the ability to create reports from file and folder comparisons. Please see Creating a File Comparison Report and Creating a Folder Comparison Report for more information.

Older versions of Merge

One way to create a permanent record of comparison results is to use the Merge printing capability in conjunction with Adobe Acrobat (see to create a PDF file. Adobe Acrobat works by adding a virtual printer to your system. When you print your file or folder comparison to the Acrobat Distiller printer, a PDF file containing whatever you have printed is created.

Although you’d need to purchase Adobe Acrobat if you don’t already have it, this solution works well for audit situations, especially since the Acrobat Reader (needed to view PDF files) is free.

Can I use Merge to compare and synchronize local files with those on a web or FTP site?

Yes. Merge contains a plugin that enables Merge to access files and folders located on an FTP server. Find out more.

How can I navigate between changes in the file comparison window?

  • The small Previous change and Next change buttons below the scroll bars can be used to jump to the previous or next change.
  • Click on the Previous change and Next change ribbon buttons to move to the previous or next change.
  • There are also several keyboard shortcuts that can be used.

What is the difference between a change and a conflict?

A conflict occurs in a three-way merging scenario where a two later revisions of the common ancestor file have been modified in different ways at the same location relative to the common ancestor file. The Automatic File Merging topic shows an example of a merging conflict. A change is simply a difference between two files. Linking lines show how the lines in one file are changed with respect to the other file.

How can I make Merge just show the changes between files?

Merge provides the ability to compress blocks of unchanged lines so that just a few lines for context are displayed. Please see the File Comparisons help topic for more details.

I’m comparing files with columns or fields of characters within which changes should be ignored. How can I tell Merge to do this?

Changes occurring within numbered columns, or column ranges, can be ignored by using the controls on the Text Comparisons options page. To omit fields or sequences of characters that don’t always appear at the same absolute position within the line, create a regular expression using the controls on the Line Expressions options page. When entering the expression, choose the Ignore sequences of characters that match the expression option to ignore changes within the matching characters. Please see the Edit Line Expression window’s help topic for more details.

How does the Hide/revealHide rows with only empty folders command work?

This command is not a toggle command. When you use it, Merge will look through the comparison results list and hide any folders that don’t contain visible files. If you use the command before the folder comparison has completed, folders could be hidden even if they eventually contain visible files when the comparison finishes. Wait until the comparison has completed before using the command.

How can I speed up large file comparisons (and recomparisons, as I edit files)?

Merge generally compares files very quickly. However, for those situations where comparisons take more time, applying the following suggestions can improve matters significantly.

  • Turn off word-wrapping (Options…Text ComparisonsDisplay). This is likely to be the single biggest potential performance gain.
  • Disable any unnecessary regular expressions (Options…Text ComparisonsExpressions).
  • Disable any unnecessary column filters (Options…Text Comparisons).
  • Enable the Options…File ComparisonsDisplayShow only # lines of context option. Note that this would only improve performance if you have left word wrapping on, but not otherwise.
  • Turn off the detailed inline highlighting of changes (Options…Text ComparisonsDisplay).
  • Uncheck the Options…Text ComparisonsSyntax HighlightingUse syntax highlighting for recognized file types option.

How can I speed up folder comparisons?

Merge is optimized to compare even large folder hierarchies very quickly. However, folder comparison performance is highly dependent upon several Merge settings. For the fastest folder comparisons:

  • Uncheck the Options…Folder ComparisonsUse filter programs for files in folder comparisons option.
  • Uncheck the Options…Folder ComparisonsGather line count statistics for inserted and removed files option.
  • Uncheck the Options…Folder ComparisonsScan contents of folders excluded by filters option, and the Scan contents of files excluded by filters option on the same page.
  • Choose the Options…Folder ComparisonsMethodFile timestamps and sizes only comparison method.
  • Check the Options…Folder ComparisonsMethodCompare byte-by-byte for files larger than # KB option, and consider reducing the file size threshold for byte-by-byte comparison option on the same page from the default 512 KB.

How can I increase the amount of memory that Merge can use for large file and folder comparisons?

64-bit versions of Merge are able to process very large file and folder comparisons and rarely run out of memory. If Merge does run out of memory while performing a comparison, it may be because Windows has been configured to use a small paging file, or no paging file at all. Configuring a paging file, enlarging it, or giving Windows the ability to manage the paging file size as it sees fit can enable Merge to run more effectively. For more information, see the Configuring a Windows Paging File topic.

How can I switch between the most recently used comparisons?

By default, the Ctrl+Tab and Ctrl+Shift+Tab keyboard shortcuts cycle through the next or previous comparisons in the order in which they are displayed by the tab strip. As of Merge 2021.5562, it is possible to change the action of these shortcuts to step through comparisons in order of their most recent use. To do this:

  1. Ensure Merge is not running.

  2. Launch the Windows Registry Editor (regedit.exe).

  3. Navigate to the HKEY_CURRENT_USER\Software\Araxis\Merge\7.1 registry key.

  4. Change the MRUTabOrder value to 1.

  5. Close the Registry Editor and run Merge.

Can I change the Merge keyboard shortcuts?

It is not possible to change the Merge keyboard shortcuts from within the application itself. However, third-party software such as the free AutoHotkey utility can be used to reassign existing keyboard shortcuts.

For example, the following steps could be used to create an AutoHotkey script to redefine Ctrl+W to close the current Merge comparison tab:

  1. Install AutoHotkey.

  2. Create an AutoHokey script Merge.ahk with the following contents:

    #If WinActive("ahk_exe Merge.exe")
    ; Ctrl+w closes the active tab
    ^w::Send ^{F4}
  3. Double-click the script to cause it to take effect.


How can I make Merge work with files and folders that have very long paths?

Merge fully supports very long file and folder paths. However, Microsoft Windows historically only supported paths with fewer than 260 characters . Windows supports much longer paths as of Windows 10 version 1607, but that support must be specifically enabled.

To enable the support for long paths in Windows, perform the following steps:

  1. Launch the Windows Registry Editor (regedit.exe).

  2. Navigate to the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\FileSystem registry key.

  3. Change the value LongPathsEnable to 1.

  4. Close the Registry Editor.

  5. Restart Windows.

Why isn’t the F7 shortcut key (move to previous difference) working for me?

It is likely that some other application on your system has intercepted the F7 key for its own purposes. In particular, we have had reports of the nVidia Desktop Manager graphics card software using F7 as a shortcut key. It is often possible to disable such software’s shortcut keys, at which point they should become available for Merge to use.

I’ve opened a file with a Far East code page, and all I can see is boxes where characters should be. Why?

You should choose a font in the Fonts and Colours options pages that is able to display all the characters for the code page that you are using. For Far East languages in particular, many of the fonts supplied with Windows are unable to display all the characters in the code pages.

How can I stop Merge from freezing when I right-click a file or folder comparison panel?

Merge enumerates Windows File Explorer context menu plugins when you right-click within a file or folder comparison to bring up the context menu. Unfortunately, some third-party File Explorer plugins do not work properly in Merge and can cause the context menus not to appear, or sometimes even freeze Merge.

If you encounter this problem, uncheck the Include ‘Compare with Araxis Merge’ in Windows File Explorer menus option on the Options…Application options page.

How can I tell whether I was given the correct serial number when I purchased Merge?

Please see Understanding Serial Numbers, Support Expiry & Upgrade/Support Entitlement for information about your serial number.

How can I prevent folder comparisons from overloading a file storage device or service (e.g. a cloud-based datastore such as Microsoft OneDrive)?

Folder comparisons rapidly make a great many file-related requests to the storage device containing the folders being compared. If that storage device is provided by a cloud-based service such as Microsoft OneDrive, the service may throttle traffic to prevent it from being overwhelmed. Should this occur, Merge will typically report that it is unable to perform the folder comparison because of a problem with the relevant device.

Temporarily unchecking the Use multiple processor threads to compare folders setting on the Folder Comparisons options page may help to prevent this problem by restricting Merge to make only one request at a time. This will likely increase the time required to perform folder comparisons.

If the problem persists even with the aforementioned setting unchecked, follow these steps to add a delay between requests made by folder comparisons:

  1. Ensure Merge is not running.

  2. Launch the Windows Registry Editor (regedit.exe).

  3. Navigate to the HKEY_CURRENT_USER\Software\Araxis\Merge\7.1 registry key.

  4. Change the IOThrottleTime value to the number of milliseconds delay to make between requests. Start with a value of, for example, 100 milliseconds. This can be increased or decreased as experimentation suggests.

  5. Close the Registry Editor and run Merge.

Information Folder comparisons are likely to take significantly longer to complete when a delay is configured.


May I link to the Merge home page?

Yes, please do! To avoid any danger of broken links, it is best if you link to or