The Options dialog enables you to customize many WinMerge features. To set WinMerge options:
-
Click → in the menu or the
button in the
toolbar.The Options dialog contains a number of pages, each containing a group of related options. You can open any page by clicking its title in the Categories list, on the left side of the dialog.
-
Configure the options you want to change using one or both of these methods:
Directly in the options pages.
Importing an options
.inifile that you exported previously (see Importing and Exporting options for details).
When you have set all your options, click to save them and dismiss the dialog.
This topic describes the options in detail. There is a section for each page in the Options dialog.
If you change options frequently for different compare or merge scenarios, or if you want to share your settings with other WinMerge users, consider saving your settings by exporting them to an options file. Then, whenever you want to use those settings, you can simply import the options file instead of setting options manually.
- To import options
-
When you want to reuse your saved options, click . In the Select file for import dialog, navigate to the saved
inifile and click .The values in your imported options file replace all existing settings.
- To export options
-
When you have set your options the way you want them, click . In the Select file for export dialog, specify a path and name for your options file (the type
iniis automatically appended), and click .In the generated text
inifile, each line contains a name-value pair that defines a single option.
The General page has these options:
Disabled(default): Compare window opens to the top of the folder or file, with no difference selected.-
Enabled: When it first opens, the Compare window selects the first difference, scrolling to the location if necessary.For a folder compare, selects the first different file or folders.
For a file compare, selects the first difference block in the files.
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MDI child window or main window(default): Lets you use the Esc key to close WinMerge windows. Pressing Esc once closes one window, so with one File Compare window open, it takes three key presses to close WinMerge: first the File Compare window, then the Folder Compare window, and finally the WinMerge window.Note that in the WinMerge command line, the
-eparameter enables you to close WinMerge by pressing Esc just once. MDI child window only: Pressing Esc closes a child window, but not the last remaining main window.Disabled: Pressing Esc does not close any WinMerge windows.
Enabled(default): The Select Files or Folders dialog checks both or all three paths as you enter them. The button remains disabled until both or all three paths are validated. Note that this checking can cause some delay.Disabled: The button in the Select Files or Folders dialog is always enabled, and attempts to open any paths you specify. Since there is no delay during validation, this can speed up the selection of paths. However, if the path cannot be opened, an error dialog is displayed.
Disabled(default): You can run multiple WinMerge instances. For example, if WinMerge is currently running and you click the WinMerge desktop shortcut, a new WinMerge window is opened.-
Enabled: Limits the WinMerge program to one instance:If WinMerge is currently running and you try to start a new instance, no new application window is opened: the current WinMerge window is used instead.
If you start a new instance with paths (for example on the command line), a new Compare window is opened in the existing WinMerge window.
Disabled(default): If you exit WinMerge while multiple Compare windows are open, WinMerge prompts you to confirm whether to close all the windows.Enabled: If you click and there are no pending file changes, WinMerge closes immediately.
Disabled(default): If you save changes to a file in WinMerge, the timestamp of the file is updated.Enabled: If you save changes to a file in WinMerge, the timestamp of the file is not changed in your file system.
Disabled(default): The WinMerge window opens when you launch WinMerge. You must then click → to open Select Files or Folders.Enabled: The Select Files or Folders dialog opens along with the WinMerge window when you launch WinMerge.
Disabled(default): When you click button, the Select File or Folders dialog will remain open instead of closing.Enabled: Clicking button closes the Select Files or Folders dialog.
Choose one of these options:
Disabled (default): No autocompletion is performed when you enter paths in the Select Files or Folders dialog.
From file system: Checks paths as you type. It attempts to locate paths in the file system that match the letters you type, and if a matching path is found, completes the path.
From Most Recent Used list: Checks paths only from the most recently used (MRU) list. This is handy when you have a limited set of paths to compare.
WinMerge allows you to suppress some common message boxes. For example, when two identical files are opened, the message box titled, The files are identical, is normally opened. If you don't want this box to display any more, you can enable (check) the option in that message box to not show the message again.
Later, you might decide that you want to see those messages again. If so, click the button to make the message boxes display again.
Note
We recommend that you not suppress messages when updating WinMerge to a newer version. The installer enables their display automatically, but if you don't use the installer, then remember to enable message display by using the button.
The options in this page enable you to change some of the ways that WinMerge detects differences, such as comparing only file size, or ignoring some types of differences, like case.
Important
Customizing difference detection can be useful during comparisons, when you might not be interested in some differences. However, these options also affect merging. For example, if you ignore whitespace changes, then indentation changes in source code files are not preserved when you merge.
For this reason, before you merge any differences, we strongly recommend resetting the options on this page to their default settings, especially the ignore options. To reset all the options on this page, click the button.
A number of options in the Compare page (described later in this section) enable you to ignore certain differences. Ignored differences are treated in special ways in WinMerge:
They are marked with the Ignored Difference color.
Ignored differences cannot be merged.
Ignored differences are not included in difference counts.
Files containing only ignored differences are marked as identical in a folder comparison.
Whitespace is the space between words and lines. It is represented in text files by special, nonprinting characters like spaces, tabs, and linefeeds. The significance of whitespace depends on how you want to read or process differences. It might be important to detect all changes in whitespace. Conversely, you might prefer to treat all whitespace the same whether one space, two spaces, an indent, or a tab. And in some structured documents (like comma-separated lists), you might want to disregard all whitespace.
Note
The effects of whitespace on changes within lines are visible only
when View line differences is enabled. This is in
contrast to difference blocks, which are always highlighted.
Example 1. Lines with different whitespace
One space between words:
Two Words
Two spaces between words:
Two Words
Tab between words:
Two Words
No spaces between words:
TwoWords
You can control whitespace detection by choosing one of these options:
- Compare
All whitespace is compared (default). If you are not sure which option your document requires, this is probably the safest choice. In the example, all lines are detected as different.
- Ignore change
Compares differences in whitespace. In the example, the first three lines have different whitespace, but are detected as identical: tabs and multiple are treated as if they are single space. The last line has no whitespace, so the difference is not ignored (in effect, the words in the last two lines are different):
- Ignore all
Ignores all whitespace characters, except linefeeds (so lines are detected and preserved in a merge). All lines in the example are detected as identical.
Related topics
The effects of whitespace settings on line differences is described in Line difference highlighting.
The Options dialog Editor page contains related options that control how whitespace is used to detect breaks between words. See Line Difference Coloring for details.
Disabled(default): Empty lines in the source files are detected and represented in the File Compare window as blank lines with the Deleted Difference colors.Enabled: Empty lines in the source files are ignored. They are represented in the File Compare window as blank lines with the Ignored Difference colors. However the difference cannot be merged.
Disabled(default): Comparisons are case-sensitive. For example,LowerCase,LOWERCASE, andlowercaseare all different.Enabled: Differences between lowercase and uppercase letters are ignored.
Disabled(default): End of line (EOL) style differences are detected. For example, if you compare two lines that have the same contents but different line endings, the lines are considered to be different. When this happens, WinMerge displays a dialog prompting you to confirm whether to detect or ignore the difference.Enabled: EOL differences are ignored.
Disabled(default): File encoding differences are detected. Also, differences between the presence and absence of BOM are detected.Enabled: File encoding differences are ignored.
Disabled(default): WinMerge compares comments in code, along with other content.Enabled: This option optimizes comparisons by detecting comments in certain programming language file types (such as C++ and Java), and ignoring them.
Disabled(default): WinMerge does not detect when differences are due to moved lines.-
Enabled: WinMerge tries to detect lines that are moved (in different locations in each file). Moved blocks are indicated by the Moved and Selected Moved difference colors. If the Location bar is displayed, corresponding difference locations in the left and right location bars are connected with a line. Showing moved blocks can make it easier to visualize changes in files, if there are not too many.For an example, see the Location pane description in Comparing and merging text files.
Disabled(default): Lines within difference blocks are shown as they occur in the source files.-
Enabled: WinMerge tries to detect lines within a difference blocks that are similar, and adds blank lines in the File panes to align them. This option is most effective when lines are quite similar; less effective if lines are too different.For an example, see the Similar lines description in Difference highlighting.
default(default): The basic greedy diff algorithm.minimal: Spend extra time to make sure the smallest possible diff is produced.patience: Use "patience diff" algorithm when generating diff.histogram: This algorithm extends the patience algorithm to "support low-occurrence common elements".none: This algorithm does not detect insertions or deletions of lines.
Enabled(default): Enable the heuristic that shifts diff hunk boundaries to make diffs easier to read. It has no effect if the Diff algorithm is default.Disabled: Disable the heuristic.
Enabled: Makes the color of the different lines ignored by line filters and substitution filters the same as the color of the identical lines.Disabled(default): Difference lines ignored by line filters and substitution filters are displayed in the color of Ignored Difference.
This option lets you determine how complete your file comparisons are. Choose one of these five choices:
- Full Contents
Default: Full comparison of files by content, with all the bells and whistles. This method invokes plugins and uses the diffutils engine for fully accurate differencing and moved block detection. This is the most complete and recommended method.
- Quick Contents
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Slimmed-down comparison of files by content. This method uses streamlined file comparison code which skips plugins and moved block detection. This method is faster than Full Contents, because it does not load the files.
Its drawback is that line filters are not applied when comparing. For example, this method sees file as different even if line filters are set to ignore all differences in the files.
- Binary Contents
This method is faster than the Quick contents compare method. However, it does not apply any plugins, line filters, 'Ignore case' option, etc. First, it compares the file sizes, and if they are different, it treats the contents of the file as different without comparing them. If the file sizes match, it simply compares the contents of the file in bytes. No file encoding detection, EOL detection, or binary file detection is performed. This compare method is good for comparing files against backed up files.
- Modified Date
Compares only the modification dates on the files, so it is far faster than either of the contents methods. But obviously, it is only as accurate as the modification dates.
- Modified Date and Size
Similar to Modified Date, but also checks file sizes when dates are identical.
- Size
Compares only file sizes, so it is fast but not as accurate as the contents methods.
This option is enabled only when the Quick Contents compare method is selected.
Disabled(default): WinMerge examines all differences in the files.-
Enabled: This option optimizes comparisons by examining files only until the first difference is found, instead always scanning the entire files.The drawback is that WinMerge may be unable to identify binary files as binary. This is likely to happen if the first difference is near the beginning of the file. If you know what kind of files you are comparing (for example, which are binary files), this option can be a good way to speed up comparisons. However, don't enable this option if you are not sure what kind of files you are comparing.
Disabled(default): Files with different timestamps are detected as different.-
Enabled: Sometimes (for example, when you use network shares) small differences in timestamps are not significant. To get more meaningful results in such situations, this option enables you to ignore time differences smaller than three seconds.This option works only with the and compare methods (described in Compare method). It has no effect with other methods.
Warning
This option should be enabled only when the time difference is detected. Otherwise, it can cause incorrect compare results.
Disabled(default): WinMerge ignore unique subfolders when comparing folders.Enabled: WinMerge also shows the content from unique subfolders.
Enabled(default): WinMerge doing a recursive comparing and also includes subfolders.Disabled: WinMerge only comparing the files in the root folder.
Disabled(default): WinMerge don't expand all subfolders after a folder compare.Enabled: WinMerge automatically expand all subfolders after finishing a folder compare.
Disabled: Is not active unless the Compare method is set to other than Full Contents compare method.-
Enabled: Is active when the Compare method is set to Full Contents compare method.Threshold size for switching to Quick Contents compare method. When Full Contents compare method is selected, files bigger (in mega bytes) than this value are compared using Quick Contents compare method.
Disabled: Is not active unless the Compare method is set to other than Full Contents and Quick Contents compare method.-
Enabled: Is active when the Compare method is set to Full Contents or Quick Contents compare method.Threshold size for switching to Binary Contents compare method. When Full Contents or Quick Contents compare method is selected, files bigger (in mega bytes) than this value are compared using Binary Contents compare method.
Specifies file name pattern for comma-separated values files to open in table format. To specify multiple items, separate them with a semicolon. By default, *.csv is specified. If you do not want to open the files with the extension .csv in table format. Delete the *.csv.
Specifies file name pattern for tab-separated values files to open in table format. To specify multiple items, separate them with a semicolon. By default, *.tsv is specified. If you do not want to open the files with the extension .tsv in table format. Delete the *.tsv.
If you want to open text files, with values separated by characters other than commas or tabs, in tabular format, specify the file name pattern and delimiter.
Enabled(default): If there is a newline character between the quote character and the next quote character, the newline character is treated as part of a value. Enable this option if you want to process CSV/TSV files that contain multiple lines in one field.Disabled: Disable the above. Disable this option when opening files with incorrect quotes.
Specifies the character that is treated as quotation marks. Delimiters within the text range enclosed by the characters specified here are treated as part of a value. This field can be empty. To open files in which the quotation marks are mere values, leave it empty or specify a character that does not exist in the file.
Enabled(default): WinMerge can syntax highlight many programming language and web formats. To see the formats that are supported by default, click → .Disabled: Syntax highlighting consumes some processing power, so if WinMerge screen updating seems to be slow, turning off this option might help.
Disabled(default): WinMerge rescans automatically when you merge a difference, or if you manually rescan (for example, click the button).-
Enabled: Forces WinMerge to rescan after every edit event (a change to files, like typing).Note
To avoid slowing down your editing, WinMerge delays automatic rescanning a little: it waits one second after each edit event. Because each new edit event resets the timer, no rescans occur until you pause or stop editing.
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Disabled(default): Assumes that files are meant to be Windows files. If a file does not use the standard Windows line ending, WinMerge considers this to be an error. It silently changes the line endings to the Windows style instead of detecting them as differences. Thus, the File Compare window status bar shows the EOL style as Win.For most situations you should leave this option disabled: the default behavior works even when comparing two files that have different line ending styles.
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Enabled: Prevents WinMerge from automatically changing line endings, so that it detects different EOL styles for every line. This might be useful for handling files from systems with different EOL styles (for example, Windows and Unix).Important
This is an advanced option for users who are familiar with EOL bytes and who want to compare files with different EOL styles inside one file. We recommend that you not enable this option unless you need this advanced functionality. Remember, this option is not required to compare two files with different EOL styles.
- Tab size
Width of a tab space. Specify a value
n: the resulting width is equivalent to that ofncharacters. Default: 4. The maximum value is 64.- Tab insert options
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Determines what kind of character is used when you insert a tab in text. Only one of these options can be enabled:
Insert Tabs (default): Uses a single tab character.
Insert Spaces: Uses one or more spaces (determined by the
Tab size) instead of a tab character. For example, with the default tab size, four spaces are inserted.
These settings enable and configure the detection of line differences (changes within the lines of difference blocks):
- View line differences
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Enabled(default): WinMerge highlights differences within lines. Also enables the → menu item.Choose one of these suboptions:
Character level: Highlights individual characters that are different. This option can be useful if you are looking for changes within words, or for file formats that do not have clear word breaks.
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Word-level (default): Highlights entire words that are different.
Break at whitespace (default): Words are assumed to be separated by whitespace characters. This usually works for typical text files.
Break at whitespace or punctuation: Considers both whitespace and punctuation characters to be word breaks. This can useful for handling lists that are separated with punctuation (like comma-separated lists).
Disabled: WinMerge does not highlight line differences, and all settings for the level and whitespace options are ignored. Also disables the → menu item.
-
- Word break characters
TBD
Related topic
Line difference highlighting explains in more detail how WinMerge detects and marks line differences.
Use this page if you want to change any of the difference colors used in the File Compare window. You can set the background, deleted, and text color.
To change a color, click in its box to open a standard Color chooser dialog. Choose one of the predefined colors or define your own custom color, then click to load the new color in the box.
To revert to the default colors of a scheme, choose a different scheme and return to the modified scheme.
By default, the WinMerge File Compare window marks the syntax of certain kinds of source code, as described in Highlight syntax. This page lists the syntax elements that are recognized, and enables you to change their text color and weight.
To revert to the default colors of a scheme, choose a different scheme and return to the modified scheme.
Use this page to change the colors used for text. First, check the option, Use customized text colors. This activates the text options. There is an option for three kinds of text: whitespace, regular text, and selected text. For each kind of text , you can choose a color for the background and the text.
By default, the WinMerge Folder Compare window use background colors to show the status from a item (equal, different, not exists on all sides or filtered).
To change a color, click in its box to open a standard Color chooser dialog. Choose one of the predefined colors or define your own custom color, then click to load the new color in the box.
To revert to the default colors of a scheme, choose a different scheme and return to the modified scheme.
This page contains options for configuring archive support using 7-Zip.
This option controls how WinMerge handles archive files (based on 7-Zip integration).
Enabled(default): WinMerge recognizes 7-Zip archives.Disabled: Turns off 7-Zip archive integration.
Disabled(default): WinMerge recognizes only archives whose file extension is known on your system (for example, in the registry or through a file association).-
Enabled: WinMerge can recognize archive files even if their file extension is not known. To recognize an archive, WinMerge searches the beginning of the file for the archive signature bytes.Tip
You can use this option to enable WinMerge to recognize Open Office files.
-
Enabled(default): Files and folders that you delete in a Folder Compare window are moved to the Recycle Bin, if it is available.Important
Remember: if the Recycle Bin on your system has been deactivated, this option does not work, and deleted files are lost!
Disabled: Files and folders deleted in a directory compare actually deleted.
The WinMerge File Compare window provides common editing functions. If you prefer using your favorite, full-featured editor, you can configure WinMerge to open an external editor from the Folder Compare context menu.
Installation configures Notepad as the default external editor, because it is found on all Windows systems. To configure a different external editor, enter the full path to its executable file.
Tip
Along with the path, you can include any command line parameters
supported by the external tool, in this format:
path to executable
-option1 -option2
...
To use the configured external editor, right-click a file in the Folder Compare window and choose → or → .
Use this field to specify your own private folder for file filters.
By default this folder is your user profile directory (for example,
Documents on Windows 10). When you create a file
filter, it is automatically added to this folder.
This page allows you to control how WinMerge creates backup files.
Specify when WinMerge should create backup files. You can enable or disable each of these options independently:
Folder compare (disabled by default): Backup files are create whenever files are overwritten (copied).
File compare (enabled by default): Backup files are created whenever files are saved.
Specify where backup files are created. Only one of these options can be enabled:
Original file's folder (enabled by default): Backup files are created in the same folder as the source file. This is usually a good choice. The down side is that cleaning up backup files in big folders can take a lot of work.
Global backup folder (disabled by default): All backup files are created in one global folder. This makes them easy to clean up. But, if there are multiple source files with same file name, then the most recent backup file overwrites the previous one of the same name.
When WinMerge creates a backup file, it appends an extension to the source file name. You can choose either or both of these extension schemes:
Append .bak extension (enabled by default): For example, the
file.txtis backed up tofile.txt.bak.-
Append timestamp (enabled by default): Timestamps are almost always unique, so this option usually avoids duplicating backup file names when the source files have the same names.
Also, storing a copy of a file each time you save it provides a way to track changes to the file. However, you should consider that this option can create a lot of files.
WinMerge detects handles file encoding transparently, and in most cases you should not need to change the default settings.This page allows you to specify the codepages of certain file formats, should you need to.
Note
A full explanation of text encoding and Windows codepages is beyond the scope of WinMerge documentation. Fortunately, there is lots of information about them on the Internet. For example, here are some places to start:
Choose one of these radio buttons to set the default codepage that WinMerge uses when handling ANSI files:
System codepage (default):The codepage used by your Windows system. This default is usually the best choice. However if you know that you are comparing files that do not use the system codepage, consider one of the other options.
According to WinMerge User Interface: The encoding used by your installation of WinMerge.
Custom codepage: Enter the codepage number explicitly. For example,
UTF-8orISO-8851-1.
Important
Uncheck this option in WinMerge.exe.
Characters conversions can result in lossy conversions and the risk is
very high. WinMerge.exe can display files only with
your current codepage.
Disabled(default): WinMerge does not read codepage information from the source files. It uses the default codepage setting instead.-
Enabled: WinMerge detects the codepage for these extensions:html,rc(resource files for VC++) andxml. The detected codepage overrides the setting for the default codepage option.This option is of interest when your documents use a codepage that is different from the codepage of your Windows configuration.
For example, you might merge two Slovak or two Japanese files in an English environment. With this option enabled (and with the required fonts), your Slovak, or Japanese, the files are displayed using Slovak, or Japanese, characters.
WinMerge also detects a codepage difference between the left/right files. To avoid lossy conversions when you merge, copy, or paste, we suggest that you ignore the codepage information.
Caution
When you copy or paste text to an external application, the external application must use the same codepage as WinMerge does. Refer to the documentation for your external editor. For copying to WinMerge, Internet Explorer offers codepage selection. If your external editor does not support custom codepages, disable this option.
The Add to context menu option enables you to
launch WinMerge directly from Windows Explorer, comparing items that you
have selected there. It is enabled or disabled by default during WinMerge
installation. If enabled, you can also enable one or both of these
options:
- Enable advanced menu
Disabled(default): Only the shortcut is included in the Windows Explorer context menu.Enabled: Replaces the shortcut in the Explorer context menu with shortcuts.
Launching WinMerge operations in Windows Explorer describes how to use the WinMerge and Compare shortcuts.