diff --git a/src/fios_gui.cpp b/src/fios_gui.cpp
--- a/src/fios_gui.cpp
+++ b/src/fios_gui.cpp
@@ -82,6 +82,7 @@ enum SaveLoadWindowWidgets {
 	SLWW_DETAILS,              ///< Panel with game details
 	SLWW_NEWGRF_INFO,          ///< Button to open NewGgrf configuration
 	SLWW_LOAD_BUTTON,          ///< Button to load game/scenario
+	SLWW_MISSING_NEWGRFS,      ///< Button to find missing NewGRFs online
 };
 
 /** Load game/scenario with optional content download */
@@ -114,6 +115,7 @@ static const NWidgetPart _nested_load_di
 		EndContainer(),
 		NWidget(WWT_PANEL, COLOUR_GREY),
 			NWidget(WWT_EMPTY, INVALID_COLOUR, SLWW_DETAILS), SetResize(1, 1), SetFill(1, 1),
+			NWidget(WWT_PUSHTXTBTN, COLOUR_GREY, SLWW_MISSING_NEWGRFS), SetDataTip(STR_NEWGRF_SETTINGS_FIND_MISSING_CONTENT_BUTTON, STR_NEWGRF_SETTINGS_FIND_MISSING_CONTENT_TOOLTIP), SetFill(1, 0), SetResize(1, 0),
 			NWidget(NWID_HORIZONTAL),
 				NWidget(NWID_HORIZONTAL, NC_EQUALSIZE),
 					NWidget(WWT_PUSHTXTBTN, COLOUR_GREY, SLWW_NEWGRF_INFO), SetDataTip(STR_INTRO_NEWGRF_SETTINGS, STR_NULL), SetFill(1, 0), SetResize(1, 0),
@@ -554,6 +556,16 @@ public:
 				}
 				break;
 
+			case SLWW_MISSING_NEWGRFS:
+				if (!_network_available) {
+					ShowErrorMessage(STR_NETWORK_ERROR_NOTAVAILABLE, INVALID_STRING_ID, WL_ERROR);
+				} else {
+#if defined(ENABLE_NETWORK)
+					ShowMissingContentWindow(_load_check_data.grfconfig);
+#endif
+				}
+				break;
+
 			case SLWW_DRIVES_DIRECTORIES_LIST: { // Click the listbox
 				int y = this->vscroll->GetScrolledRowFromWidget(pt.y, this, SLWW_DRIVES_DIRECTORIES_LIST, WD_FRAMERECT_TOP);
 				if (y == INT_MAX) return;
@@ -699,6 +711,8 @@ public:
 							this->selected == NULL || _load_check_data.HasErrors() || !(_load_check_data.grf_compatibility != GLC_NOT_FOUND || _settings_client.gui.UserIsAllowedToChangeNewGRFs()));
 					this->SetWidgetDisabledState(SLWW_NEWGRF_INFO,
 							!_load_check_data.HasNewGrfs());
+					this->SetWidgetDisabledState(SLWW_MISSING_NEWGRFS,
+							!_load_check_data.HasNewGrfs() || _load_check_data.grf_compatibility == GLC_ALL_GOOD);
 				}
 				break;
 			case 2:
diff --git a/src/network/network_content.h b/src/network/network_content.h
--- a/src/network/network_content.h
+++ b/src/network/network_content.h
@@ -151,6 +151,8 @@ extern ClientNetworkContentSocketHandler
 
 void ShowNetworkContentListWindow(ContentVector *cv = NULL, ContentType type = CONTENT_TYPE_END);
 
+void ShowMissingContentWindow(const struct GRFConfig *list);
+
 #else
 static inline void ShowNetworkContentListWindow() {}
 #endif /* ENABLE_NETWORK */
diff --git a/src/network/network_gui.cpp b/src/network/network_gui.cpp
--- a/src/network/network_gui.cpp
+++ b/src/network/network_gui.cpp
@@ -19,6 +19,7 @@
 #include "network_gamelist.h"
 #include "network.h"
 #include "network_base.h"
+#include "network_content.h"
 #include "../gui.h"
 #include "network_udp.h"
 #include "../window_func.h"
@@ -105,6 +106,8 @@ enum NetworkGameWindowWidgets {
 	NGWW_REFRESH,       ///< 'Refresh server' button
 	NGWW_NEWGRF,        ///< 'NewGRF Settings' button
 	NGWW_NEWGRF_SEL,    ///< Selection 'widget' to hide the NewGRF settings
+	NGWW_NEWGRF_MISSING,     ///< 'Find missing NewGRF online' button
+	NGWW_NEWGRF_MISSING_SEL, ///< Selection widget for the above button
 
 	NGWW_FIND,          ///< 'Find server' button
 	NGWW_ADD,           ///< 'Add server' button
@@ -603,6 +606,7 @@ public:
 
 		/* 'NewGRF Settings' button invisible if no NewGRF is used */
 		this->GetWidget<NWidgetStacked>(NGWW_NEWGRF_SEL)->SetDisplayedPlane(sel == NULL || !sel->online || sel->info.grfconfig == NULL);
+		this->GetWidget<NWidgetStacked>(NGWW_NEWGRF_MISSING_SEL)->SetDisplayedPlane(sel == NULL || !sel->online || sel->info.grfconfig == NULL || !sel->info.version_compatible || sel->info.compatible);
 
 		this->DrawWidgets();
 		/* Edit box to set client name */
@@ -776,6 +780,10 @@ public:
 			case NGWW_NEWGRF: // NewGRF Settings
 				if (this->server != NULL) ShowNewGRFSettings(false, false, false, &this->server->info.grfconfig);
 				break;
+
+			case NGWW_NEWGRF_MISSING: // Find missing content online
+				if (this->server != NULL) ShowMissingContentWindow(this->server->info.grfconfig);
+				break;
 		}
 	}
 
@@ -960,6 +968,12 @@ static const NWidgetPart _nested_network
 				NWidget(WWT_PANEL, COLOUR_LIGHT_BLUE, NGWW_DETAILS),
 					NWidget(NWID_VERTICAL, NC_EQUALSIZE), SetPIP(5, 5, 5),
 						NWidget(WWT_EMPTY, INVALID_COLOUR, NGWW_DETAILS_SPACER), SetMinimalSize(140, 155), SetResize(0, 1), SetFill(1, 1), // Make sure it's at least this wide
+						NWidget(NWID_HORIZONTAL, NC_NONE), SetPIP(5, 5, 5),
+							NWidget(NWID_SELECTION, INVALID_COLOUR, NGWW_NEWGRF_MISSING_SEL),
+								NWidget(WWT_PUSHTXTBTN, COLOUR_WHITE, NGWW_NEWGRF_MISSING), SetFill(1, 0), SetDataTip(STR_NEWGRF_SETTINGS_FIND_MISSING_CONTENT_BUTTON, STR_NEWGRF_SETTINGS_FIND_MISSING_CONTENT_TOOLTIP),
+								NWidget(NWID_SPACER), SetFill(1, 0),
+							EndContainer(),
+						EndContainer(),
 						NWidget(NWID_HORIZONTAL, NC_EQUALSIZE), SetPIP(5, 5, 5),
 							NWidget(NWID_SPACER), SetFill(1, 0),
 							NWidget(NWID_SELECTION, INVALID_COLOUR, NGWW_NEWGRF_SEL),
diff --git a/src/newgrf_gui.cpp b/src/newgrf_gui.cpp
--- a/src/newgrf_gui.cpp
+++ b/src/newgrf_gui.cpp
@@ -1196,20 +1196,7 @@ struct NewGRFWindow : public QueryString
 #if defined(ENABLE_NETWORK)
 					this->DeleteChildWindows(WC_QUERY_STRING); // Remove the parameter query window
 
-					/* Only show the things in the current list, or everything when nothing's selected */
-					ContentVector cv;
-					for (const GRFConfig *c = this->actives; c != NULL; c = c->next) {
-						if (c->status != GCS_NOT_FOUND && !HasBit(c->flags, GCF_COMPATIBLE)) continue;
-
-						ContentInfo *ci = new ContentInfo();
-						ci->type = CONTENT_TYPE_NEWGRF;
-						ci->state = ContentInfo::DOES_NOT_EXIST;
-						ttd_strlcpy(ci->name, c->GetName(), lengthof(ci->name));
-						ci->unique_id = BSWAP32(c->ident.grfid);
-						memcpy(ci->md5sum, HasBit(c->flags, GCF_COMPATIBLE) ? c->original_md5sum : c->ident.md5sum, sizeof(ci->md5sum));
-						*cv.Append() = ci;
-					}
-					ShowNetworkContentListWindow(cv.Length() == 0 ? NULL : &cv, CONTENT_TYPE_NEWGRF);
+					ShowMissingContentWindow(this->actives);
 #endif
 				}
 				break;
@@ -1506,6 +1493,30 @@ private:
 	}
 };
 
+#if defined(ENABLE_NETWORK)
+/**
+ * Show the content list window with all missing grfs from the given list.
+ * @param list The list of grfs to check for missings / not exactly matching ones.
+ */
+void ShowMissingContentWindow(const GRFConfig *list)
+{
+	/* Only show the things in the current list, or everything when nothing's selected */
+	ContentVector cv;
+	for (const GRFConfig *c = list; c != NULL; c = c->next) {
+		if (c->status != GCS_NOT_FOUND && !HasBit(c->flags, GCF_COMPATIBLE)) continue;
+
+		ContentInfo *ci = new ContentInfo();
+		ci->type = CONTENT_TYPE_NEWGRF;
+		ci->state = ContentInfo::DOES_NOT_EXIST;
+		ttd_strlcpy(ci->name, c->GetName(), lengthof(ci->name));
+		ci->unique_id = BSWAP32(c->ident.grfid);
+		memcpy(ci->md5sum, HasBit(c->flags, GCF_COMPATIBLE) ? c->original_md5sum : c->ident.md5sum, sizeof(ci->md5sum));
+		*cv.Append() = ci;
+	}
+	ShowNetworkContentListWindow(cv.Length() == 0 ? NULL : &cv, CONTENT_TYPE_NEWGRF);
+}
+#endif
+
 Listing NewGRFWindow::last_sorting     = {false, 0};
 Filtering NewGRFWindow::last_filtering = {false, 0};