NAME

       git-mergetool - Run merge conflict resolution tools to resolve merge conflicts

SYNOPSIS

       git mergetool [--tool=<tool>] [-y | --[no-]prompt] [<file>...]

DESCRIPTION

       Use git mergetool to run one of several merge utilities to resolve merge conflicts. It is typically run
       after git merge.

       If one or more <file> parameters are given, the merge tool program will be run to resolve differences on
       each file (skipping those without conflicts). Specifying a directory will include all unresolved files in
       that path. If no <file> names are specified, git mergetool will run the merge tool program on every file
       with merge conflicts.

OPTIONS

       -t <tool>, --tool=<tool>
           Use the merge resolution program specified by <tool>. Valid values include emerge, gvimdiff, kdiff3,
           meld, vimdiff, and tortoisemerge. Run git mergetool --tool-help for the list of valid <tool>
           settings.

           If a merge resolution program is not specified, git mergetool will use the configuration variable
           merge.tool. If the configuration variable merge.tool is not set, git mergetool will pick a suitable
           default.

           You can explicitly provide a full path to the tool by setting the configuration variable
           mergetool.<tool>.path. For example, you can configure the absolute path to kdiff3 by setting
           mergetool.kdiff3.path. Otherwise, git mergetool assumes the tool is available in PATH.

           Instead of running one of the known merge tool programs, git mergetool can be customized to run an
           alternative program by specifying the command line to invoke in a configuration variable
           mergetool.<tool>.cmd.

           When git mergetool is invoked with this tool (either through the -t or --tool option or the
           merge.tool configuration variable) the configured command line will be invoked with $BASE set to the
           name of a temporary file containing the common base for the merge, if available; $LOCAL set to the
           name of a temporary file containing the contents of the file on the current branch; $REMOTE set to
           the name of a temporary file containing the contents of the file to be merged, and $MERGED set to the
           name of the file to which the merge tool should write the result of the merge resolution.

           If the custom merge tool correctly indicates the success of a merge resolution with its exit code,
           then the configuration variable mergetool.<tool>.trustExitCode can be set to true. Otherwise, git
           mergetool will prompt the user to indicate the success of the resolution after the custom tool has
           exited.

       --tool-help
           Print a list of merge tools that may be used with --tool.

       -y, --no-prompt
           Don’t prompt before each invocation of the merge resolution program. This is the default if the merge
           resolution program is explicitly specified with the --tool option or with the merge.tool
           configuration variable.

       --prompt
           Prompt before each invocation of the merge resolution program to give the user a chance to skip the
           path.

       -g, --gui
           When git-mergetool is invoked with the -g or --gui option the default merge tool will be read from
           the configured merge.guitool variable instead of merge.tool. If merge.guitool is not set, we will
           fallback to the tool configured under merge.tool.

       --no-gui
           This overrides a previous -g or --gui setting and reads the default merge tool will be read from the
           configured merge.tool variable.

       -O<orderfile>
           Process files in the order specified in the <orderfile>, which has one shell glob pattern per line.
           This overrides the diff.orderFile configuration variable (see git-config(1)). To cancel
           diff.orderFile, use -O/dev/null.

CONFIGURATION

       mergetool.<tool>.path
           Override the path for the given tool. This is useful in case your tool is not in the PATH.

       mergetool.<tool>.cmd
           Specify the command to invoke the specified merge tool. The specified command is evaluated in shell
           with the following variables available: BASE is the name of a temporary file containing the common
           base of the files to be merged, if available; LOCAL is the name of a temporary file containing the
           contents of the file on the current branch; REMOTE is the name of a temporary file containing the
           contents of the file from the branch being merged; MERGED contains the name of the file to which the
           merge tool should write the results of a successful merge.

       mergetool.<tool>.hideResolved
           Allows the user to override the global mergetool.hideResolved value for a specific tool. See
           mergetool.hideResolved for the full description.

       mergetool.<tool>.trustExitCode
           For a custom merge command, specify whether the exit code of the merge command can be used to
           determine whether the merge was successful. If this is not set to true then the merge target file
           timestamp is checked and the merge assumed to have been successful if the file has been updated,
           otherwise the user is prompted to indicate the success of the merge.

       mergetool.meld.hasOutput
           Older versions of meld do not support the --output option. Git will attempt to detect whether meld
           supports --output by inspecting the output of meld --help. Configuring mergetool.meld.hasOutput will
           make Git skip these checks and use the configured value instead. Setting mergetool.meld.hasOutput to
           true tells Git to unconditionally use the --output option, and false avoids using --output.

       mergetool.meld.useAutoMerge
           When the --auto-merge is given, meld will merge all non-conflicting parts automatically, highlight
           the conflicting parts and wait for user decision. Setting mergetool.meld.useAutoMerge to true tells
           Git to unconditionally use the --auto-merge option with meld. Setting this value to auto makes git
           detect whether --auto-merge is supported and will only use --auto-merge when available. A value of
           false avoids using --auto-merge altogether, and is the default value.

       mergetool.hideResolved
           During a merge Git will automatically resolve as many conflicts as possible and write the MERGED file
           containing conflict markers around any conflicts that it cannot resolve; LOCAL and REMOTE normally
           represent the versions of the file from before Git’s conflict resolution. This flag causes LOCAL and
           REMOTE to be overwriten so that only the unresolved conflicts are presented to the merge tool. Can be
           configured per-tool via the mergetool.<tool>.hideResolved configuration variable. Defaults to false.

       mergetool.keepBackup
           After performing a merge, the original file with conflict markers can be saved as a file with a .orig
           extension. If this variable is set to false then this file is not preserved. Defaults to true (i.e.
           keep the backup files).

       mergetool.keepTemporaries
           When invoking a custom merge tool, Git uses a set of temporary files to pass to the tool. If the tool
           returns an error and this variable is set to true, then these temporary files will be preserved,
           otherwise they will be removed after the tool has exited. Defaults to false.

       mergetool.writeToTemp
           Git writes temporary BASE, LOCAL, and REMOTE versions of conflicting files in the worktree by
           default. Git will attempt to use a temporary directory for these files when set true. Defaults to
           false.

       mergetool.prompt
           Prompt before each invocation of the merge resolution program.

TEMPORARY FILES

       git mergetool creates *.orig backup files while resolving merges. These are safe to remove once a file
       has been merged and its git mergetool session has completed.

       Setting the mergetool.keepBackup configuration variable to false causes git mergetool to automatically
       remove the backup as files are successfully merged.

GIT

       Part of the git(1) suite

Git 2.34.1                                         07/09/2025                                   GIT-MERGETOOL(1)