diff --git a/backends/imgui_impl_allegro5.cpp b/backends/imgui_impl_allegro5.cpp
index bb6660d88..6ee88a184 100644
--- a/backends/imgui_impl_allegro5.cpp
+++ b/backends/imgui_impl_allegro5.cpp
@@ -524,7 +524,7 @@ void ImGui_ImplAllegro5_SetDisplay(ALLEGRO_DISPLAY* display)
     if (bd->VertexDecl)
     {
         al_destroy_vertex_decl(bd->VertexDecl);
-        bd->VertexDecl = NULL;
+        bd->VertexDecl = nullptr;
     }
 
     if (bd->Display && !bd->VertexDecl)
diff --git a/backends/imgui_impl_allegro5.h b/backends/imgui_impl_allegro5.h
index 622430432..135c4ff8a 100644
--- a/backends/imgui_impl_allegro5.h
+++ b/backends/imgui_impl_allegro5.h
@@ -38,7 +38,7 @@ IMGUI_IMPL_API void     ImGui_ImplAllegro5_SetDisplay(ALLEGRO_DISPLAY* display);
 IMGUI_IMPL_API bool     ImGui_ImplAllegro5_CreateDeviceObjects();
 IMGUI_IMPL_API void     ImGui_ImplAllegro5_InvalidateDeviceObjects();
 
-// (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = NULL to handle this manually.
+// (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = nullptr to handle this manually.
 IMGUI_IMPL_API void     ImGui_ImplAllegro5_UpdateTexture(ImTextureData* tex);
 
 #endif // #ifndef IMGUI_DISABLE
diff --git a/backends/imgui_impl_dx10.h b/backends/imgui_impl_dx10.h
index 38ecbdfe3..9d7fb68ae 100644
--- a/backends/imgui_impl_dx10.h
+++ b/backends/imgui_impl_dx10.h
@@ -32,7 +32,7 @@ IMGUI_IMPL_API void     ImGui_ImplDX10_RenderDrawData(ImDrawData* draw_data);
 IMGUI_IMPL_API bool     ImGui_ImplDX10_CreateDeviceObjects();
 IMGUI_IMPL_API void     ImGui_ImplDX10_InvalidateDeviceObjects();
 
-// (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = NULL to handle this manually.
+// (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = nullptr to handle this manually.
 IMGUI_IMPL_API void     ImGui_ImplDX10_UpdateTexture(ImTextureData* tex);
 
 // [BETA] Selected render state data shared with callbacks.
diff --git a/backends/imgui_impl_dx11.h b/backends/imgui_impl_dx11.h
index c120bf093..1df4f3695 100644
--- a/backends/imgui_impl_dx11.h
+++ b/backends/imgui_impl_dx11.h
@@ -34,7 +34,7 @@ IMGUI_IMPL_API void     ImGui_ImplDX11_RenderDrawData(ImDrawData* draw_data);
 IMGUI_IMPL_API bool     ImGui_ImplDX11_CreateDeviceObjects();
 IMGUI_IMPL_API void     ImGui_ImplDX11_InvalidateDeviceObjects();
 
-// (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = NULL to handle this manually.
+// (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = nullptr to handle this manually.
 IMGUI_IMPL_API void     ImGui_ImplDX11_UpdateTexture(ImTextureData* tex);
 
 // [BETA] Selected render state data shared with callbacks.
diff --git a/backends/imgui_impl_dx12.cpp b/backends/imgui_impl_dx12.cpp
index 14c0fc60f..056d23a6c 100644
--- a/backends/imgui_impl_dx12.cpp
+++ b/backends/imgui_impl_dx12.cpp
@@ -875,7 +875,7 @@ bool ImGui_ImplDX12_Init(ImGui_ImplDX12_InitInfo* init_info)
     init_info = &bd->InitInfo;
 
     bd->pd3dDevice = init_info->Device;
-    IM_ASSERT(init_info->CommandQueue != NULL);
+    IM_ASSERT(init_info->CommandQueue != nullptr);
     bd->pCommandQueue = init_info->CommandQueue;
     bd->RTVFormat = init_info->RTVFormat;
     bd->DSVFormat = init_info->DSVFormat;
diff --git a/backends/imgui_impl_dx12.h b/backends/imgui_impl_dx12.h
index 3bb66c1fb..8d61dae77 100644
--- a/backends/imgui_impl_dx12.h
+++ b/backends/imgui_impl_dx12.h
@@ -64,7 +64,7 @@ IMGUI_IMPL_API bool     ImGui_ImplDX12_Init(ID3D12Device* device, int num_frames
 IMGUI_IMPL_API bool     ImGui_ImplDX12_CreateDeviceObjects();
 IMGUI_IMPL_API void     ImGui_ImplDX12_InvalidateDeviceObjects();
 
-// (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = NULL to handle this manually.
+// (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = nullptr to handle this manually.
 IMGUI_IMPL_API void     ImGui_ImplDX12_UpdateTexture(ImTextureData* tex);
 
 // [BETA] Selected render state data shared with callbacks.
diff --git a/backends/imgui_impl_dx9.h b/backends/imgui_impl_dx9.h
index 600f0a750..021439b9a 100644
--- a/backends/imgui_impl_dx9.h
+++ b/backends/imgui_impl_dx9.h
@@ -31,7 +31,7 @@ IMGUI_IMPL_API void     ImGui_ImplDX9_RenderDrawData(ImDrawData* draw_data);
 IMGUI_IMPL_API bool     ImGui_ImplDX9_CreateDeviceObjects();
 IMGUI_IMPL_API void     ImGui_ImplDX9_InvalidateDeviceObjects();
 
-// (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = NULL to handle this manually.
+// (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = nullptr to handle this manually.
 IMGUI_IMPL_API void     ImGui_ImplDX9_UpdateTexture(ImTextureData* tex);
 
 #endif // #ifndef IMGUI_DISABLE
diff --git a/backends/imgui_impl_glfw.cpp b/backends/imgui_impl_glfw.cpp
index 82c512fee..f166b45d2 100644
--- a/backends/imgui_impl_glfw.cpp
+++ b/backends/imgui_impl_glfw.cpp
@@ -251,10 +251,10 @@ static bool ImGui_ImplGlfw_IsWayland()
     return glfwGetPlatform() == GLFW_PLATFORM_WAYLAND;
 #else
     const char* version = glfwGetVersionString();
-    if (strstr(version, "Wayland") == NULL) // e.g. Ubuntu 22.04 ships with GLFW 3.3.6 compiled without Wayland
+    if (strstr(version, "Wayland") == nullptr) // e.g. Ubuntu 22.04 ships with GLFW 3.3.6 compiled without Wayland
         return false;
 #ifdef GLFW_EXPOSE_NATIVE_X11
-    if (glfwGetX11Display() != NULL)
+    if (glfwGetX11Display() != nullptr)
         return false;
 #endif
     return true;
diff --git a/backends/imgui_impl_metal.h b/backends/imgui_impl_metal.h
index 2a9a26a02..8af2c8b6b 100644
--- a/backends/imgui_impl_metal.h
+++ b/backends/imgui_impl_metal.h
@@ -39,7 +39,7 @@ IMGUI_IMPL_API void ImGui_ImplMetal_RenderDrawData(ImDrawData* drawData,
 IMGUI_IMPL_API bool ImGui_ImplMetal_CreateDeviceObjects(id<MTLDevice> device);
 IMGUI_IMPL_API void ImGui_ImplMetal_DestroyDeviceObjects();
 
-// (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = NULL to handle this manually.
+// (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = nullptr to handle this manually.
 IMGUI_IMPL_API void ImGui_ImplMetal_UpdateTexture(ImTextureData* tex);
 
 #endif
@@ -67,7 +67,7 @@ IMGUI_IMPL_API void ImGui_ImplMetal_RenderDrawData(ImDrawData* draw_data,
 IMGUI_IMPL_API bool ImGui_ImplMetal_CreateDeviceObjects(MTL::Device* device);
 IMGUI_IMPL_API void ImGui_ImplMetal_DestroyDeviceObjects();
 
-// (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = NULL to handle this manually.
+// (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = nullptr to handle this manually.
 IMGUI_IMPL_API void ImGui_ImplMetal_UpdateTexture(ImTextureData* tex);
 
 #endif
diff --git a/backends/imgui_impl_opengl2.h b/backends/imgui_impl_opengl2.h
index 014a03aca..65b0fe0b4 100644
--- a/backends/imgui_impl_opengl2.h
+++ b/backends/imgui_impl_opengl2.h
@@ -37,7 +37,7 @@ IMGUI_IMPL_API void     ImGui_ImplOpenGL2_RenderDrawData(ImDrawData* draw_data);
 IMGUI_IMPL_API bool     ImGui_ImplOpenGL2_CreateDeviceObjects();
 IMGUI_IMPL_API void     ImGui_ImplOpenGL2_DestroyDeviceObjects();
 
-// (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = NULL to handle this manually.
+// (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = nullptr to handle this manually.
 IMGUI_IMPL_API void     ImGui_ImplOpenGL2_UpdateTexture(ImTextureData* tex);
 
 #endif // #ifndef IMGUI_DISABLE
diff --git a/backends/imgui_impl_opengl3.cpp b/backends/imgui_impl_opengl3.cpp
index 133b0ed27..6348b01b0 100644
--- a/backends/imgui_impl_opengl3.cpp
+++ b/backends/imgui_impl_opengl3.cpp
@@ -41,7 +41,7 @@
 //  2023-05-09: OpenGL: Support for glBindSampler() backup/restore on ES3. (#6375)
 //  2023-04-18: OpenGL: Restore front and back polygon mode separately when supported by context. (#6333)
 //  2023-03-23: OpenGL: Properly restoring "no shader program bound" if it was the case prior to running the rendering function. (#6267, #6220, #6224)
-//  2023-03-15: OpenGL: Fixed GL loader crash when GL_VERSION returns NULL. (#6154, #4445, #3530)
+//  2023-03-15: OpenGL: Fixed GL loader crash when GL_VERSION returns nullptr. (#6154, #4445, #3530)
 //  2023-03-06: OpenGL: Fixed restoration of a potentially deleted OpenGL program, by calling glIsProgram(). (#6220, #6224)
 //  2022-11-09: OpenGL: Reverted use of glBufferSubData(), too many corruptions issues + old issues seemingly can't be reproed with Intel drivers nowadays (revert 2021-12-15 and 2022-05-23 changes).
 //  2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
diff --git a/backends/imgui_impl_opengl3.h b/backends/imgui_impl_opengl3.h
index b72b5c887..aabe04b07 100644
--- a/backends/imgui_impl_opengl3.h
+++ b/backends/imgui_impl_opengl3.h
@@ -40,7 +40,7 @@ IMGUI_IMPL_API void     ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data);
 IMGUI_IMPL_API bool     ImGui_ImplOpenGL3_CreateDeviceObjects();
 IMGUI_IMPL_API void     ImGui_ImplOpenGL3_DestroyDeviceObjects();
 
-// (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = NULL to handle this manually.
+// (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = nullptr to handle this manually.
 IMGUI_IMPL_API void     ImGui_ImplOpenGL3_UpdateTexture(ImTextureData* tex);
 
 // Configuration flags to add in your imconfig file:
diff --git a/backends/imgui_impl_sdl2.cpp b/backends/imgui_impl_sdl2.cpp
index 2049f117b..4fb9c4d99 100644
--- a/backends/imgui_impl_sdl2.cpp
+++ b/backends/imgui_impl_sdl2.cpp
@@ -684,7 +684,7 @@ static void ImGui_ImplSDL2_UpdateMouseData()
         // Note that SDL_GetGlobalMouseState() is in theory slow on X11, but this only runs on rather specific cases. If a problem we may provide a way to opt-out this feature.
         SDL_Window* hovered_window = SDL_GetMouseFocus();
         const bool is_relative_mouse_mode = SDL_GetRelativeMouseMode() != 0;
-        if (hovered_window == NULL && bd->MouseCanUseGlobalState && bd->MouseButtonsDown == 0 && !is_relative_mouse_mode)
+        if (hovered_window == nullptr && bd->MouseCanUseGlobalState && bd->MouseButtonsDown == 0 && !is_relative_mouse_mode)
         {
             // Single-viewport mode: mouse position in client window coordinates (io.MousePos is (0,0) when the mouse is on the upper-left corner of the app window)
             int mouse_x, mouse_y;
diff --git a/backends/imgui_impl_sdl3.cpp b/backends/imgui_impl_sdl3.cpp
index a1a3eeb86..f8bacc51b 100644
--- a/backends/imgui_impl_sdl3.cpp
+++ b/backends/imgui_impl_sdl3.cpp
@@ -191,7 +191,7 @@ static void ImGui_ImplSDL3_UpdateIme()
         SDL_StopTextInput(bd->ImeWindow);
         bd->ImeWindow = nullptr;
     }
-    if ((!bd->ImeDirty && bd->ImeWindow == window) || (window == NULL))
+    if ((!bd->ImeDirty && bd->ImeWindow == window) || (window == nullptr))
         return;
 
     // Start/update current input
@@ -663,7 +663,7 @@ static void ImGui_ImplSDL3_UpdateMouseData()
         // Note that SDL_GetGlobalMouseState() is in theory slow on X11, but this only runs on rather specific cases. If a problem we may provide a way to opt-out this feature.
         SDL_Window* hovered_window = SDL_GetMouseFocus();
         const bool is_relative_mouse_mode = SDL_GetWindowRelativeMouseMode(bd->Window);
-        if (hovered_window == NULL && bd->MouseCanUseGlobalState && bd->MouseButtonsDown == 0 && !is_relative_mouse_mode)
+        if (hovered_window == nullptr && bd->MouseCanUseGlobalState && bd->MouseButtonsDown == 0 && !is_relative_mouse_mode)
         {
             // Single-viewport mode: mouse position in client window coordinates (io.MousePos is (0,0) when the mouse is on the upper-left corner of the app window)
             float mouse_x, mouse_y;
diff --git a/backends/imgui_impl_sdlgpu3.h b/backends/imgui_impl_sdlgpu3.h
index cde9c5fe7..12b6528f3 100644
--- a/backends/imgui_impl_sdlgpu3.h
+++ b/backends/imgui_impl_sdlgpu3.h
@@ -48,7 +48,7 @@ IMGUI_IMPL_API void     ImGui_ImplSDLGPU3_RenderDrawData(ImDrawData* draw_data,
 IMGUI_IMPL_API void     ImGui_ImplSDLGPU3_CreateDeviceObjects();
 IMGUI_IMPL_API void     ImGui_ImplSDLGPU3_DestroyDeviceObjects();
 
-// (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = NULL to handle this manually.
+// (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = nullptr to handle this manually.
 IMGUI_IMPL_API void     ImGui_ImplSDLGPU3_UpdateTexture(ImTextureData* tex);
 
 // [BETA] Selected render state data shared with callbacks.
diff --git a/backends/imgui_impl_sdlrenderer2.h b/backends/imgui_impl_sdlrenderer2.h
index a62e60927..860e95507 100644
--- a/backends/imgui_impl_sdlrenderer2.h
+++ b/backends/imgui_impl_sdlrenderer2.h
@@ -39,7 +39,7 @@ IMGUI_IMPL_API void     ImGui_ImplSDLRenderer2_RenderDrawData(ImDrawData* draw_d
 IMGUI_IMPL_API void     ImGui_ImplSDLRenderer2_CreateDeviceObjects();
 IMGUI_IMPL_API void     ImGui_ImplSDLRenderer2_DestroyDeviceObjects();
 
-// (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = NULL to handle this manually.
+// (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = nullptr to handle this manually.
 IMGUI_IMPL_API void     ImGui_ImplSDLRenderer2_UpdateTexture(ImTextureData* tex);
 
 // [BETA] Selected render state data shared with callbacks.
diff --git a/backends/imgui_impl_sdlrenderer3.h b/backends/imgui_impl_sdlrenderer3.h
index 618cc2430..f5f53b9d2 100644
--- a/backends/imgui_impl_sdlrenderer3.h
+++ b/backends/imgui_impl_sdlrenderer3.h
@@ -39,7 +39,7 @@ IMGUI_IMPL_API void     ImGui_ImplSDLRenderer3_RenderDrawData(ImDrawData* draw_d
 IMGUI_IMPL_API void     ImGui_ImplSDLRenderer3_CreateDeviceObjects();
 IMGUI_IMPL_API void     ImGui_ImplSDLRenderer3_DestroyDeviceObjects();
 
-// (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = NULL to handle this manually.
+// (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = nullptr to handle this manually.
 IMGUI_IMPL_API void     ImGui_ImplSDLRenderer3_UpdateTexture(ImTextureData* tex);
 
 // [BETA] Selected render state data shared with callbacks.
diff --git a/backends/imgui_impl_vulkan.cpp b/backends/imgui_impl_vulkan.cpp
index f01d2145d..8f4bd5a62 100644
--- a/backends/imgui_impl_vulkan.cpp
+++ b/backends/imgui_impl_vulkan.cpp
@@ -1156,7 +1156,7 @@ void ImGui_ImplVulkan_CreateMainPipeline(const ImGui_ImplVulkan_PipelineInfo* pi
 
 #ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
     VkPipelineRenderingCreateInfoKHR* pipeline_rendering_create_info = &pipeline_info->PipelineRenderingCreateInfo;
-    if (v->UseDynamicRendering && pipeline_rendering_create_info->pColorAttachmentFormats != NULL)
+    if (v->UseDynamicRendering && pipeline_rendering_create_info->pColorAttachmentFormats != nullptr)
     {
         // Deep copy buffer to reduce error-rate for end user (#8282)
         ImVector<VkFormat> formats;
diff --git a/backends/imgui_impl_vulkan.h b/backends/imgui_impl_vulkan.h
index 0ebe1d42d..4ad33b8f3 100644
--- a/backends/imgui_impl_vulkan.h
+++ b/backends/imgui_impl_vulkan.h
@@ -142,7 +142,7 @@ IMGUI_IMPL_API void             ImGui_ImplVulkan_SetMinImageCount(uint32_t min_i
 // Else, the pipeline can be created, or re-created, using ImGui_ImplVulkan_CreateMainPipeline() before rendering.
 IMGUI_IMPL_API void             ImGui_ImplVulkan_CreateMainPipeline(const ImGui_ImplVulkan_PipelineInfo* info);
 
-// (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = NULL to handle this manually.
+// (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = nullptr to handle this manually.
 IMGUI_IMPL_API void             ImGui_ImplVulkan_UpdateTexture(ImTextureData* tex);
 
 // Register a texture (VkDescriptorSet == ImTextureID)
diff --git a/backends/imgui_impl_wgpu.h b/backends/imgui_impl_wgpu.h
index f17fe6c25..7ab3dd31f 100644
--- a/backends/imgui_impl_wgpu.h
+++ b/backends/imgui_impl_wgpu.h
@@ -72,7 +72,7 @@ IMGUI_IMPL_API void ImGui_ImplWGPU_RenderDrawData(ImDrawData* draw_data, WGPURen
 IMGUI_IMPL_API bool ImGui_ImplWGPU_CreateDeviceObjects();
 IMGUI_IMPL_API void ImGui_ImplWGPU_InvalidateDeviceObjects();
 
-// (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = NULL to handle this manually.
+// (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = nullptr to handle this manually.
 IMGUI_IMPL_API void ImGui_ImplWGPU_UpdateTexture(ImTextureData* tex);
 
 // [BETA] Selected render state data shared with callbacks.