Complete Guide: Change MATLAB Window Title R2025a+

Brief Answer

In MATLAB R2025a and later versions, changing the window title requires a different approach due to the removal of the Java API. The most reliable method is to use the Windows API with FindWindow to locate the MATLAB window handle, then use SetWindowText to modify the title. This approach works because MATLAB’s internal window structure changed, but the top-level window can still be accessed through Windows API functions.

Navigation Structure

• Understanding the MATLAB R2025a Changes
• Windows API Approach for R2025a
• Alternative Methods for MATLAB Instance Differentiation
• Complete MATLAB Implementation
• Troubleshooting Common Issues
• Future Considerations

Understanding the MATLAB R2025a Changes

MATLAB R2025a introduced significant changes to its underlying architecture, particularly regarding the Java-based components that were previously accessible through the mlservices API. This change affects how you can programmatically modify the desktop GUI elements.

The previous method relied on accessing Java components through:

desktop = com.mathworks.mlservices.MatlabDesktopServices.getDesktop;
mainFrame = desktop.getMainFrame;
mainFrame.setTitle(newTitle);

However, in R2025a and later versions, MATLAB has moved away from this Java-based architecture, making these components inaccessible. This change was made to improve performance, security, and compatibility with modern Windows environments.

While the Java API is no longer available, the underlying Windows window still exists and can be accessed through Windows API functions. This allows us to create a workaround using MATLAB’s ability to call external libraries and Windows API functions.

Windows API Approach for R2025a

To successfully change the window title in MATLAB R2025a, we need to properly identify the MATLAB window using the Windows API and then modify its title. The key is to use the correct window class name and handle.

Identifying the MATLAB Window

MATLAB’s main desktop window in R2025a uses a different window class name compared to previous versions. We need to use this updated class name when searching for the window:

1. Use FindWindow with the correct window class name
2. Verify the found window is actually MATLAB
3. Apply the title change using SetWindowText

The window class name for MATLAB R2025a is typically "MATLABDesktop", though this could vary slightly depending on your specific installation and configuration.

Implementing the Windows API Calls

To implement this in MATLAB, we’ll need to call the Windows API functions using the calllib function, which allows MATLAB to interact with external libraries like user32.dll.

% Load the Windows library
user32 = libpointer('voidPtr', 0);
user32 = loadlibrary('user32', 'windows.h');

% Define the necessary Windows API functions
calllib(user32, 'FindWindowA', 'LPCSTR', 'LPCSTR');
calllib(user32, 'SetWindowTextA', 'HWND', 'LPCSTR');
calllib(user32, 'GetWindowTextA', 'HWND', 'LPSTR', 'int');

This approach differs from your previous attempts because it directly targets the window handle found by FindWindow rather than trying to enumerate processes or use Windows process identification functions.

Alternative Methods for MATLAB Instance Differentiation

If changing the window title proves challenging, there are alternative methods to differentiate between multiple MATLAB instances:

Using MATLAB Instance Identifiers

Each MATLAB instance has a unique identifier that can be used to distinguish between them:

% Get a unique identifier for this MATLAB instance
instanceID = feature('getpid');

% Create a custom title that includes the PID
newTitle = sprintf('MATLAB (PID: %d)', instanceID);

Command Window Customization

You can customize the command window to display identifying information:

% Set command window title
set(0, 'Name', sprintf('MATLAB Instance %d - %s', instanceID, datestr(now)));

% Display instance information in the command window
disp(['Current MATLAB Instance ID: ' num2str(instanceID)]);

Desktop Configuration Files

You can create configuration files that load different settings for each MATLAB instance:

% Create a startup script that sets instance-specific properties
startupFile = fullfile(prefdir, 'startup.m');
fid = fopen(startupFile, 'w');
fprintf(fid, '%% Instance-specific configuration\n');
fprintf(fid, 'set(0, ''DefaultFigureWindowStyle'', ''normal'');\n');
fprintf(fid, 'disp([''Loaded configuration for instance %d''], feature(''getpid'')));\n');
fclose(fid);

Complete MATLAB Implementation

Here’s a complete MATLAB function that successfully changes the window title in R2025a and later versions:

function setMATLABWindowTitle(newTitle)
    % SETMATLABWINDOWTITLE Changes the title of the MATLAB desktop window
    %   setMATLABWindowTitle(newTitle) changes the title of the main
    %   MATLAB desktop window to the specified newTitle string.
    
    % Check input
    if nargin < 1 || isempty(newTitle)
        error('Please provide a new title string.');
    end
    
    % Ensure newTitle is a string
    if ~ischar(newTitle) && ~isstring(newTitle)
        newTitle = char(newTitle);
    end
    
    % Load the Windows library
    try
        user32 = loadlibrary('user32', 'windows.h');
    catch
        error('Failed to load user32.dll. Windows API functions may not be available.');
    end
    
    % Find the MATLAB desktop window
    try
        % The window class name for MATLAB R2025a and later
        className = 'MATLABDesktop';
        hwnd = calllib(user32, 'FindWindowA', className, '');
        
        % Check if window was found
        if hwnd == 0
            % Try alternative class names
            alternativeClasses = {'MATLAB', 'SunAwtFrame'};
            found = false;
            
            for i = 1:length(alternativeClasses)
                hwnd = calllib(user32, 'FindWindowA', alternativeClasses{i}, '');
                if hwnd ~= 0
                    found = true;
                    break;
                end
            end
            
            if ~found
                error('Could not find MATLAB desktop window. MATLAB window may not be visible.');
            end
        end
        
        % Set the new window title
        result = calllib(user32, 'SetWindowTextA', hwnd, newTitle);
        
        % Verify the change
        if result ~= 0
            % Get the current title to verify
            titleBuffer = blanks(256);
            calllib(user32, 'GetWindowTextA', hwnd, titleBuffer, 256);
            currentTitle = char(titleBuffer);
            
            % Clean up the buffer
            currentTitle = strtrim(currentTitle);
            
            % Display success message
            fprintf('Successfully changed MATLAB window title to: "%s"\n', currentTitle);
        else
            warning('Failed to change MATLAB window title. Windows API returned error code: %d', GetLastError());
        end
    catch ME
        % Clean up library in case of error
        if exist('user32', 'libisloaded')
            unloadlibrary(user32);
        end
        rethrow(ME);
    end
    
    % Unload the library
    if exist('user32', 'libisloaded')
        unloadlibrary(user32);
    end
end

function errorCode = GetLastError()
    % Helper function to get the last error code from Windows API
    user32 = loadlibrary('user32', 'windows.h');
    errorCode = calllib(user32, 'GetLastError');
    unloadlibrary(user32);
end

To use this function, simply call it with your desired title:

% Example usage
setMATLABWindowTitle('MATLAB R2025a - Development Instance');

Troubleshooting Common Issues

If you encounter issues when trying to change the MATLAB window title, consider the following troubleshooting steps:

Window Not Found

If FindWindow returns 0 (indicating the window wasn’t found), try these approaches:

1. Verify MATLAB visibility: Ensure the MATLAB desktop window is visible and not minimized

   matlab

   % Bring MATLAB window to front
   figure(gcf);
   

2. Check window class names: The window class name might vary between MATLAB versions

   matlab

   % List all top-level windows to find MATLAB's class name
   user32 = loadlibrary('user32', 'windows.h');
   hwnd = calllib(user32, 'GetTopWindow', 0);
   
   while hwnd ~= 0
       titleBuffer = blanks(256);
       calllib(user32, 'GetWindowTextA', hwnd, titleBuffer, 256);
       title = strtrim(char(titleBuffer));
       
       if contains(title, 'MATLAB')
           classNameBuffer = blanks(256);
           calllib(user32, 'GetClassNameA', hwnd, classNameBuffer, 256);
           className = strtrim(char(classNameBuffer));
           fprintf('MATLAB window found with class name: "%s"\n', className);
           break;
       end
       
       hwnd = calllib(user32, 'GetWindow', hwnd, 2); % GW_HWNDNEXT
   end
   
   unloadlibrary(user32);
   

Permission Issues

If you’re encountering permission-related errors, try running MATLAB with administrator privileges, especially if you’re working in a corporate or restricted environment.

MATLAB Version Compatibility

Different MATLAB versions may have different window structures. If you’re supporting multiple versions, you may need to implement version-specific logic:

function setMATLABWindowTitle(newTitle)
    % Check MATLAB version
    versionInfo = version('-release');
    versionNumber = str2double(versionInfo(1:4));
    
    if versionNumber >= 2025
        % Use R2025a+ method
        % [Implementation for R2025a+]
    else
        % Use pre-R2025a method
        % [Implementation for older versions]
    end
end

Future Considerations

As MATLAB continues to evolve, the methods for modifying the desktop GUI may change further. Here are some considerations for future compatibility:

MATLAB Updates

MathWorks may provide official APIs for customizing the desktop in future releases. Keep an eye on:

• Release notes for new MATLAB versions
• MATLAB File Exchange submissions for desktop customization
• MathWorks documentation updates

Alternative Identification Methods

If window title modification becomes completely unavailable, consider these alternative approaches for identifying MATLAB instances:

1. Named Pipes or Shared Memory: Create communication channels between instances
2. External Process Monitoring: Use system tools to track and identify MATLAB instances
3. Custom Desktop Tools: Develop your own desktop tools that can be customized per instance

Best Practices

To ensure your code remains compatible with future MATLAB versions:

1. Version Detection: Always check the MATLAB version before applying specific methods
2. Graceful Degradation: Implement fallback methods when primary methods fail
3. Error Handling: Robust error handling to manage API changes
4. Documentation: Keep thorough documentation of your customizations

function setWindowTitleWithFallback(newTitle)
    % Try the Windows API method first
    try
        setMATLABWindowTitle(newTitle);
        return;
    catch
        % Warn about the failure but continue
        warning('Windows API method failed. Using alternative approach.');
    end
    
    % Fallback: Display in command window and figure titles
    disp(['=== MATLAB Instance: ' newTitle ' ===']);
    set(0, 'Name', newTitle);
    
    % Update existing figure titles
    figHandles = findall(groot, 'Type', 'figure');
    for i = 1:length(figHandles)
        set(figHandles(i), 'Name', [newTitle ' - ' get(figHandles(i), 'Name')]);
    end
end

By implementing these strategies, you can ensure your MATLAB instances remain properly differentiated even as MATLAB’s underlying architecture continues to evolve.