diff --git a/glfw/cocoa_platform.h b/glfw/cocoa_platform.h
index 7faeb7296..326ff4ef4 100644
--- a/glfw/cocoa_platform.h
+++ b/glfw/cocoa_platform.h
@@ -215,6 +215,10 @@ typedef struct _GLFWlibraryNS
 
     // the callback to handle url open events
     GLFWhandleurlopen url_open_callback;
+
+    // Active drag session (NSDraggingSession*) and view (NSView*)
+    id drag_session;
+    id drag_view;
 } _GLFWlibraryNS;
 
 // Cocoa-specific per-monitor data
diff --git a/glfw/cocoa_window.m b/glfw/cocoa_window.m
index 3c4c7b8fc..bdec278cd 100644
--- a/glfw/cocoa_window.m
+++ b/glfw/cocoa_window.m
@@ -4069,7 +4069,9 @@ _glfwPlatformStartDrag(_GLFWwindow* window, const GLFWimage* thumbnail) {@autore
         [dragItems addObject:dragItem];
     }
 
-    [v beginDraggingSessionWithItems:dragItems event:event source:[v draggingSource]];
+    [_glfw.ns.drag_session release];
+    _glfw.ns.drag_session = [[v beginDraggingSessionWithItems:dragItems event:event source:[v draggingSource]] retain];
+    _glfw.ns.drag_view = v;
     return 0;
 }}
 
@@ -4192,10 +4194,59 @@ _glfwPlatformStartDrag(_GLFWwindow* window, const GLFWimage* thumbnail) {@autore
 @end
 
 void
-_glfwPlatformFreeDragSourceData(void) { }
+_glfwPlatformFreeDragSourceData(void) {
+    [_glfw.ns.drag_session release];
+    _glfw.ns.drag_session = nil;
+    _glfw.ns.drag_view = nil;
+}
 
 int
-_glfwPlatformChangeDragImage(const GLFWimage *thumbnail) { (void)thumbnail; return 0; /* TODO: Implement me */ }
+_glfwPlatformChangeDragImage(const GLFWimage *thumbnail) {@autoreleasepool{
+    if (!_glfw.ns.drag_session || !thumbnail || !thumbnail->pixels) return 0;
+    _GLFWwindow *window = _glfwWindowForId(_glfw.drag.window_id);
+    CGFloat scaleFactor = 1.0;
+    if (window) {
+        NSWindow *nsw = window->ns.object;
+        scaleFactor = [nsw backingScaleFactor];
+        if (scaleFactor == 0) scaleFactor = [NSScreen mainScreen].backingScaleFactor;
+    }
+    NSBitmapImageRep* imageRep = [[NSBitmapImageRep alloc]
+        initWithBitmapDataPlanes:NULL
+                        pixelsWide:thumbnail->width
+                        pixelsHigh:thumbnail->height
+                    bitsPerSample:8
+                    samplesPerPixel:4
+                        hasAlpha:YES
+                        isPlanar:NO
+                    colorSpaceName:NSDeviceRGBColorSpace
+                        bytesPerRow:thumbnail->width * 4
+                    bitsPerPixel:32];
+    if (!imageRep) return ENOMEM;
+    memcpy([imageRep bitmapData], thumbnail->pixels, thumbnail->width * thumbnail->height * 4);
+    NSSize pointSize = NSMakeSize(thumbnail->width / scaleFactor, thumbnail->height / scaleFactor);
+    [imageRep setSize:pointSize];
+    NSImage* image = [[[NSImage alloc] initWithSize:pointSize] autorelease];
+    if (!image) { [imageRep release]; return ENOMEM; }
+    [image addRepresentation:imageRep];
+    [imageRep release];
+
+    NSArray *classes = @[[NSPasteboardItem class], [NSFilePromiseProvider class]];
+    [((NSDraggingSession*)_glfw.ns.drag_session)
+        enumerateDraggingItemsWithOptions:0
+        forView:(NSView*)_glfw.ns.drag_view
+        classes:classes
+        searchOptions:@{}
+        usingBlock:^(NSDraggingItem *draggingItem, NSInteger idx, BOOL *stop) {
+            if (idx == 0) {
+                NSRect frame = [draggingItem draggingFrame];
+                [draggingItem setDraggingFrame:NSMakeRect(frame.origin.x, frame.origin.y,
+                                                          pointSize.width, pointSize.height)
+                                      contents:image];
+                *stop = YES;
+            }
+        }];
+    return 0;
+}}
 
 int
 _glfwPlatformDragDataReady(const char *mime_type) {
diff --git a/glfw/wl_window.c b/glfw/wl_window.c
index b8b08be8a..006dfda12 100644
--- a/glfw/wl_window.c
+++ b/glfw/wl_window.c
@@ -3190,7 +3190,29 @@ add_drag_watch(int fd) {
 }
 
 int
-_glfwPlatformChangeDragImage(const GLFWimage *thumbnail) { (void)thumbnail; return 0; /* TODO: Implement me */ }
+_glfwPlatformChangeDragImage(const GLFWimage *thumbnail) {
+    if (!_glfw.wl.drag.drag_icon || !thumbnail || !thumbnail->pixels) return 0;
+    struct wl_buffer* icon_buffer = createShmBuffer(thumbnail, false, true);
+    if (!icon_buffer) return ENOMEM;
+    if (_glfw.wl.drag.drag_viewport) {
+        _GLFWwindow *window = _glfwWindowForId(_glfw.drag.window_id);
+        double f_scale = window ? _glfwWaylandWindowScale(window) : 1.0;
+        int logical_width = (int)(thumbnail->width / f_scale);
+        int logical_height = (int)(thumbnail->height / f_scale);
+        wp_viewport_set_destination(_glfw.wl.drag.drag_viewport, logical_width, logical_height);
+    } else {
+        _GLFWwindow *window = _glfwWindowForId(_glfw.drag.window_id);
+        if (window) {
+            int scale = _glfwWaylandIntegerWindowScale(window);
+            wl_surface_set_buffer_scale(_glfw.wl.drag.drag_icon, scale);
+        }
+    }
+    wl_surface_attach(_glfw.wl.drag.drag_icon, icon_buffer, 0, 0);
+    wl_surface_damage(_glfw.wl.drag.drag_icon, 0, 0, INT32_MAX, INT32_MAX);
+    wl_surface_commit(_glfw.wl.drag.drag_icon);
+    wl_buffer_destroy(icon_buffer);
+    return 0;
+}
 
 int
 _glfwPlatformDragDataReady(const char *mime_type) {
diff --git a/glfw/x11_window.c b/glfw/x11_window.c
index 62985bee5..5d52d5e91 100644
--- a/glfw/x11_window.c
+++ b/glfw/x11_window.c
@@ -103,6 +103,7 @@ static void handle_drag_button_release(Time timestamp);
 static void handle_xdnd_status(const XClientMessageEvent *event);
 static void handle_xdnd_finished(const XClientMessageEvent *event);
 static bool create_drag_thumbnail(const GLFWimage* thumbnail, int x, int y);
+static bool render_drag_thumbnail_to_pixmap(const GLFWimage* thumbnail);
 
 static void
 handleEvents(monotonic_t timeout) {
@@ -4062,6 +4063,97 @@ send_xdnd_drop(Window target, Time timestamp) {
     XFlush(_glfw.x11.display);
 }
 
+// Render thumbnail pixels into _glfw.x11.drag.thumbnail_pixmap / thumbnail_gc.
+// thumbnail_window must already exist. On success returns true.
+static bool
+render_drag_thumbnail_to_pixmap(const GLFWimage* thumbnail) {
+    // Free any previous pixmap / GC
+    if (_glfw.x11.drag.thumbnail_gc != None) {
+        XFreeGC(_glfw.x11.display, _glfw.x11.drag.thumbnail_gc);
+        _glfw.x11.drag.thumbnail_gc = None;
+    }
+    if (_glfw.x11.drag.thumbnail_pixmap != None) {
+        XFreePixmap(_glfw.x11.display, _glfw.x11.drag.thumbnail_pixmap);
+        _glfw.x11.drag.thumbnail_pixmap = None;
+    }
+
+    _glfw.x11.drag.thumbnail_pixmap = XCreatePixmap(
+        _glfw.x11.display,
+        _glfw.x11.drag.thumbnail_window,
+        thumbnail->width,
+        thumbnail->height,
+        DefaultDepth(_glfw.x11.display, _glfw.x11.screen)
+    );
+    if (!_glfw.x11.drag.thumbnail_pixmap) return false;
+
+    _glfw.x11.drag.thumbnail_gc = XCreateGC(_glfw.x11.display, _glfw.x11.drag.thumbnail_pixmap, 0, NULL);
+    if (!_glfw.x11.drag.thumbnail_gc) {
+        XFreePixmap(_glfw.x11.display, _glfw.x11.drag.thumbnail_pixmap);
+        _glfw.x11.drag.thumbnail_pixmap = None;
+        return false;
+    }
+
+    Visual* visual = DefaultVisual(_glfw.x11.display, _glfw.x11.screen);
+    XImage* ximage = XCreateImage(
+        _glfw.x11.display,
+        visual,
+        DefaultDepth(_glfw.x11.display, _glfw.x11.screen),
+        ZPixmap,
+        0,
+        NULL,
+        thumbnail->width,
+        thumbnail->height,
+        32,
+        0
+    );
+    if (!ximage) {
+        XFreeGC(_glfw.x11.display, _glfw.x11.drag.thumbnail_gc);
+        XFreePixmap(_glfw.x11.display, _glfw.x11.drag.thumbnail_pixmap);
+        _glfw.x11.drag.thumbnail_gc = None;
+        _glfw.x11.drag.thumbnail_pixmap = None;
+        return false;
+    }
+
+    int pixels_size = thumbnail->width * thumbnail->height * 4;
+    unsigned char* ximage_data = malloc(pixels_size);
+    if (!ximage_data) {
+        XDestroyImage(ximage);
+        XFreeGC(_glfw.x11.display, _glfw.x11.drag.thumbnail_gc);
+        XFreePixmap(_glfw.x11.display, _glfw.x11.drag.thumbnail_pixmap);
+        _glfw.x11.drag.thumbnail_gc = None;
+        _glfw.x11.drag.thumbnail_pixmap = None;
+        return false;
+    }
+    ximage->data = (char*)ximage_data;
+
+    const unsigned char* src = thumbnail->pixels;
+    for (int i = 0; i < thumbnail->width * thumbnail->height; i++) {
+        unsigned char r = src[i * 4 + 0];
+        unsigned char g = src[i * 4 + 1];
+        unsigned char b = src[i * 4 + 2];
+        unsigned char a = src[i * 4 + 3];
+        if (a < 255) {
+            r = (r * a) / 255;
+            g = (g * a) / 255;
+            b = (b * a) / 255;
+        }
+        unsigned long pixel;
+        if (ximage->byte_order == LSBFirst)
+            pixel = ((unsigned long)a << 24) | ((unsigned long)r << 16) | ((unsigned long)g << 8) | b;
+        else
+            pixel = ((unsigned long)b << 24) | ((unsigned long)g << 16) | ((unsigned long)r << 8) | a;
+        XPutPixel(ximage, i % thumbnail->width, i / thumbnail->width, pixel);
+    }
+
+    XPutImage(_glfw.x11.display, _glfw.x11.drag.thumbnail_pixmap, _glfw.x11.drag.thumbnail_gc,
+              ximage, 0, 0, 0, 0, thumbnail->width, thumbnail->height);
+    XDestroyImage(ximage);
+
+    XSetWindowBackgroundPixmap(_glfw.x11.display, _glfw.x11.drag.thumbnail_window,
+                               _glfw.x11.drag.thumbnail_pixmap);
+    return true;
+}
+
 // Create thumbnail window for drag operation
 static bool
 create_drag_thumbnail(const GLFWimage* thumbnail, int x, int y) {
@@ -4091,108 +4183,12 @@ create_drag_thumbnail(const GLFWimage* thumbnail, int x, int y) {
         return false;
     }
 
-    // Create pixmap for the thumbnail image
-    _glfw.x11.drag.thumbnail_pixmap = XCreatePixmap(
-        _glfw.x11.display,
-        _glfw.x11.drag.thumbnail_window,
-        thumbnail->width,
-        thumbnail->height,
-        DefaultDepth(_glfw.x11.display, _glfw.x11.screen)
-    );
-
-    if (!_glfw.x11.drag.thumbnail_pixmap) {
+    if (!render_drag_thumbnail_to_pixmap(thumbnail)) {
         XDestroyWindow(_glfw.x11.display, _glfw.x11.drag.thumbnail_window);
         _glfw.x11.drag.thumbnail_window = None;
         return false;
     }
 
-    // Create GC for drawing
-    _glfw.x11.drag.thumbnail_gc = XCreateGC(_glfw.x11.display, _glfw.x11.drag.thumbnail_pixmap, 0, NULL);
-    if (!_glfw.x11.drag.thumbnail_gc) {
-        XFreePixmap(_glfw.x11.display, _glfw.x11.drag.thumbnail_pixmap);
-        XDestroyWindow(_glfw.x11.display, _glfw.x11.drag.thumbnail_window);
-        _glfw.x11.drag.thumbnail_window = None;
-        _glfw.x11.drag.thumbnail_pixmap = None;
-        return false;
-    }
-
-    // Convert RGBA image data to XImage and draw to pixmap
-    Visual* visual = DefaultVisual(_glfw.x11.display, _glfw.x11.screen);
-    XImage* ximage = XCreateImage(
-        _glfw.x11.display,
-        visual,
-        DefaultDepth(_glfw.x11.display, _glfw.x11.screen),
-        ZPixmap,
-        0,  // offset
-        NULL,  // data (will be set below)
-        thumbnail->width,
-        thumbnail->height,
-        32,  // bitmap_pad
-        0    // bytes_per_line (auto-calculate)
-    );
-
-    if (!ximage) {
-        XFreeGC(_glfw.x11.display, _glfw.x11.drag.thumbnail_gc);
-        XFreePixmap(_glfw.x11.display, _glfw.x11.drag.thumbnail_pixmap);
-        XDestroyWindow(_glfw.x11.display, _glfw.x11.drag.thumbnail_window);
-        _glfw.x11.drag.thumbnail_window = None;
-        _glfw.x11.drag.thumbnail_pixmap = None;
-        _glfw.x11.drag.thumbnail_gc = None;
-        return false;
-    }
-
-    // Allocate buffer for XImage
-    int pixels_size = thumbnail->width * thumbnail->height * 4;
-    unsigned char* ximage_data = malloc(pixels_size);
-    if (!ximage_data) {
-        XDestroyImage(ximage);
-        XFreeGC(_glfw.x11.display, _glfw.x11.drag.thumbnail_gc);
-        XFreePixmap(_glfw.x11.display, _glfw.x11.drag.thumbnail_pixmap);
-        XDestroyWindow(_glfw.x11.display, _glfw.x11.drag.thumbnail_window);
-        _glfw.x11.drag.thumbnail_window = None;
-        _glfw.x11.drag.thumbnail_pixmap = None;
-        _glfw.x11.drag.thumbnail_gc = None;
-        return false;
-    }
-
-    ximage->data = (char*)ximage_data;
-
-    // Convert RGBA to the format expected by XImage
-    const unsigned char* src = thumbnail->pixels;
-    for (int i = 0; i < thumbnail->width * thumbnail->height; i++) {
-        unsigned long pixel;
-        unsigned char r = src[i * 4 + 0];
-        unsigned char g = src[i * 4 + 1];
-        unsigned char b = src[i * 4 + 2];
-        unsigned char a = src[i * 4 + 3];
-
-        // Premultiply alpha
-        if (a < 255) {
-            r = (r * a) / 255;
-            g = (g * a) / 255;
-            b = (b * a) / 255;
-        }
-
-        // Convert to X11 pixel format (typically BGRA on little-endian)
-        if (ximage->byte_order == LSBFirst) {
-            pixel = (a << 24) | (r << 16) | (g << 8) | b;
-        } else {
-            pixel = (b << 24) | (g << 16) | (r << 8) | a;
-        }
-
-        XPutPixel(ximage, i % thumbnail->width, i / thumbnail->width, pixel);
-    }
-
-    // Draw the image to the pixmap
-    XPutImage(_glfw.x11.display, _glfw.x11.drag.thumbnail_pixmap, _glfw.x11.drag.thumbnail_gc,
-              ximage, 0, 0, 0, 0, thumbnail->width, thumbnail->height);
-
-    // Clean up XImage (including its data)
-    XDestroyImage(ximage);  // This also frees ximage_data
-
-    // Set the pixmap as the window's background
-    XSetWindowBackgroundPixmap(_glfw.x11.display, _glfw.x11.drag.thumbnail_window, _glfw.x11.drag.thumbnail_pixmap);
-
     // Map the window to make it visible
     XMapRaised(_glfw.x11.display, _glfw.x11.drag.thumbnail_window);
     XFlush(_glfw.x11.display);
@@ -4475,7 +4471,32 @@ _glfwPlatformFreeDragSourceData(void) {
 }
 
 int
-_glfwPlatformChangeDragImage(const GLFWimage *thumbnail) { (void)thumbnail; return 0; /* TODO: Implement me */ }
+_glfwPlatformChangeDragImage(const GLFWimage *thumbnail) {
+    if (!_glfw.x11.drag.active) return 0;
+    if (!thumbnail || !thumbnail->pixels || thumbnail->width <= 0 || thumbnail->height <= 0) return 0;
+
+    if (_glfw.x11.drag.thumbnail_window == None) {
+        // No thumbnail window yet; query cursor position and create one
+        Window root_return, child_return;
+        int root_x, root_y, win_x, win_y;
+        unsigned int mask_return;
+        XQueryPointer(_glfw.x11.display, _glfw.x11.root,
+                      &root_return, &child_return,
+                      &root_x, &root_y, &win_x, &win_y, &mask_return);
+        if (!create_drag_thumbnail(thumbnail, root_x + 10, root_y + 10)) return EIO;
+        return 0;
+    }
+
+    // Resize the existing window to match the new thumbnail dimensions
+    XResizeWindow(_glfw.x11.display, _glfw.x11.drag.thumbnail_window,
+                  thumbnail->width, thumbnail->height);
+
+    if (!render_drag_thumbnail_to_pixmap(thumbnail)) return EIO;
+
+    XClearWindow(_glfw.x11.display, _glfw.x11.drag.thumbnail_window);
+    XFlush(_glfw.x11.display);
+    return 0;
+}
 
 int
 _glfwPlatformDragDataReady(const char *mime_type) {