diff --git a/src/FileManager.cpp b/src/FileManager.cpp
index 3aac6fc..36eedb4 100644
--- a/src/FileManager.cpp
+++ b/src/FileManager.cpp
@@ -26,8 +26,10 @@
 #include "Functions.h"
 #include <SDL.h>
 #include <SDL_syswm.h>
+#ifndef __EMSCRIPTEN__
 #include <archive.h>
 #include <archive_entry.h>
+#endif
 
 using namespace std;
 
@@ -48,7 +50,9 @@ using namespace std;
 #endif
 
 //Included for the downloadFile method.
+#ifndef __EMSCRIPTEN__
 #include <curl/curl.h>
+#endif
 
 //Under Windows there's just one userpath.
 #ifdef WIN32
@@ -546,6 +550,12 @@ bool downloadFile(const string &path, const string &destination) {
 	return status;
 }
 
+#ifdef __EMSCRIPTEN__
+// Browser build: no network access (no add-ons).
+bool downloadFile(const string &path, FILE* destination) {
+	return false;
+}
+#else
 bool downloadFile(const string &path, FILE* destination) {
 	CURL* curl=curl_easy_init();
 
@@ -585,11 +595,18 @@ bool downloadFile(const string &path, FILE* destination) {
 	return (res==0);
 }
 
+#endif
+
 size_t writeData(void *ptr, size_t size, size_t nmemb, void *stream){
 	return fwrite(ptr, size, nmemb, (FILE *)stream);
 }
 
 
+#ifdef __EMSCRIPTEN__
+bool extractFile(const string &fileName, const string &destination) {
+	return false;
+}
+#else
 bool extractFile(const string &fileName, const string &destination) {
 	//Create the archive we're going to extract.
 	archive* file;
@@ -642,6 +659,7 @@ bool extractFile(const string &fileName, const string &destination) {
     archive_read_free(file);
 	return true;
 }
+#endif
 
 bool dirExists(const char* dir){
 #if defined(WIN32)
@@ -795,6 +813,7 @@ bool renameDirectory(const char* oldPath,const char* newPath){
 }
 
 
+#ifndef __EMSCRIPTEN__
 void copyData(archive* file, archive* dest) {
 	int status;
 	const void* buff;
@@ -822,6 +841,7 @@ void copyData(archive* file, archive* dest) {
 		}
 	}
 }
+#endif
 
 bool copyFile(const char* source,const char* dest){
 	//Open the source file.
diff --git a/src/Functions.cpp b/src/Functions.cpp
index 9e171a1..d2e2b59 100644
--- a/src/Functions.cpp
+++ b/src/Functions.cpp
@@ -869,6 +869,18 @@ void flipScreen(SDL_Renderer& renderer){
     SDL_RenderPresent(&renderer);
 }
 
+#ifdef __EMSCRIPTEN__
+#include <emscripten.h>
+// Browser build: the game only writes settings and statistics on exit; the page calls this when
+// the tab is hidden or closed.
+extern "C" EMSCRIPTEN_KEEPALIVE void fredygames_save(){
+	if(settings){
+		saveSettings();
+		statsMgr.saveFile(getUserPath(USER_CONFIG)+"statistics");
+	}
+}
+#endif
+
 void clean(){
 	//Save statistics
 	statsMgr.saveFile(getUserPath(USER_CONFIG)+"statistics");	
diff --git a/src/Main.cpp b/src/Main.cpp
index 6c8db3a..df63dbf 100644
--- a/src/Main.cpp
+++ b/src/Main.cpp
@@ -25,6 +25,9 @@
 #include "StatisticsManager.h"
 #include "Timer.h"
 #include <SDL.h>
+#ifdef __EMSCRIPTEN__
+#include <emscripten.h>
+#endif
 #include <stdlib.h>
 #include <time.h>
 #include <stdio.h>
@@ -234,6 +237,11 @@ int main(int argc, char** argv) {
 		if(t>0){
 			SDL_Delay(t);
 		}
+#ifdef __EMSCRIPTEN__
+		else{
+			emscripten_sleep(0);
+		}
+#endif
 	}
 
 	//The game has ended, save the settings just to be sure.
diff --git a/src/Settings.cpp b/src/Settings.cpp
index bdc988d..df79317 100644
--- a/src/Settings.cpp
+++ b/src/Settings.cpp
@@ -37,7 +37,11 @@ Settings::Settings(const string& fileName): fileName(fileName){
 	settings["height"]="600";
 	settings["resizable"]="1";
 	settings["theme"]="%DATA%/themes/Cloudscape";
+#ifdef __EMSCRIPTEN__
+	settings["internet"]="0";
+#else
 	settings["internet"]="1";
+#endif
 	settings["lastlevelpack"]="tutorial";
 	settings["internet-proxy"]="";
 	settings["lang"]="";
diff --git a/src/TitleMenu.cpp b/src/TitleMenu.cpp
index 4ef5404..b9a7b1d 100644
--- a/src/TitleMenu.cpp
+++ b/src/TitleMenu.cpp
@@ -126,6 +126,11 @@ void Menu::handleEvents(ImageManager& imageManager, SDL_Renderer& renderer){
 			setNextState(STATE_LEVEL_EDIT_SELECT);
 			break;
 		case 4:
+#ifdef __EMSCRIPTEN__
+			// Browser build: add-ons are downloaded from the internet, which this version never does.
+			msgBox(imageManager,renderer,_("Addons are not available in this version of the game."),MsgBoxOKOnly,_("Addons"));
+			break;
+#endif
 			//Check if internet is enabled.
 			if(!getSettings()->getBoolValue("internet")){
                 msgBox(imageManager,renderer,_("Enable internet in order to install addons."),MsgBoxOKOnly,_("Internet disabled"));