diff --git a/CMakeLists.txt b/CMakeLists.txt
index ad5e14c3..e4aaf88e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -638,13 +638,13 @@ if(WEBP_BUILD_EXTRAS)
                                                   ${CMAKE_CURRENT_BINARY_DIR})
 
   # vwebp_sdl
-  find_package(SDL)
-  if(WEBP_BUILD_VWEBP AND SDL_FOUND)
+  find_package(SDL2 QUIET)
+  if(WEBP_BUILD_VWEBP AND SDL2_FOUND)
     add_executable(vwebp_sdl ${VWEBP_SDL_SRCS})
-    target_link_libraries(vwebp_sdl ${SDL_LIBRARY} imageioutil webp)
+    target_link_libraries(vwebp_sdl ${SDL2_LIBRARIES} imageioutil webp)
     target_include_directories(
       vwebp_sdl PRIVATE ${CMAKE_CURRENT_SOURCE_DIR} ${CMAKE_CURRENT_BINARY_DIR}
-                        ${CMAKE_CURRENT_BINARY_DIR}/src ${SDL_INCLUDE_DIR})
+                        ${CMAKE_CURRENT_BINARY_DIR}/src ${SDL2_INCLUDE_DIRS})
     set(WEBP_HAVE_SDL 1)
     target_compile_definitions(vwebp_sdl PUBLIC WEBP_HAVE_SDL)
   endif()
@@ -661,31 +661,43 @@ if(WEBP_BUILD_WEBP_JS)
   else()
     set(emscripten_stack_size "-sTOTAL_STACK=5MB")
   endif()
+  # Set SDL2 flags so that ports are downloaded by emscripten.
+  set(EMSCRIPTEN_SDL2_FLAGS "-sUSE_SDL=2 -sUSE_SDL_IMAGE=2")
+  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${EMSCRIPTEN_SDL2_FLAGS}")
   # wasm2js does not support SIMD.
   if(NOT WEBP_ENABLE_SIMD)
     # JavaScript version
+    find_package(SDL2 QUIET)
     add_executable(webp_js ${CMAKE_CURRENT_SOURCE_DIR}/extras/webp_to_sdl.c)
-    target_link_libraries(webp_js webpdecoder SDL)
+    target_link_libraries(webp_js webpdecoder SDL2)
     target_include_directories(webp_js PRIVATE ${CMAKE_CURRENT_BINARY_DIR})
     set(WEBP_HAVE_SDL 1)
     set_target_properties(
       webp_js
-      PROPERTIES LINK_FLAGS "-sWASM=0 ${emscripten_stack_size} \
+      PROPERTIES
+        LINK_FLAGS
+        "-sWASM=0 ${emscripten_stack_size} \
          -sEXPORTED_FUNCTIONS=_WebPToSDL -sINVOKE_RUN=0 \
-         -sEXPORTED_RUNTIME_METHODS=cwrap")
+         -sEXPORTED_RUNTIME_METHODS=cwrap ${EMSCRIPTEN_SDL2_FLAGS} \
+         -sALLOW_MEMORY_GROWTH"
+    )
     set_target_properties(webp_js PROPERTIES OUTPUT_NAME webp)
     target_compile_definitions(webp_js PUBLIC EMSCRIPTEN WEBP_HAVE_SDL)
   endif()
 
   # WASM version
   add_executable(webp_wasm ${CMAKE_CURRENT_SOURCE_DIR}/extras/webp_to_sdl.c)
-  target_link_libraries(webp_wasm webpdecoder SDL)
+  target_link_libraries(webp_wasm webpdecoder SDL2)
   target_include_directories(webp_wasm PRIVATE ${CMAKE_CURRENT_BINARY_DIR})
   set_target_properties(
     webp_wasm
-    PROPERTIES LINK_FLAGS "-sWASM=1 ${emscripten_stack_size} \
+    PROPERTIES
+      LINK_FLAGS
+      "-sWASM=1 ${emscripten_stack_size} \
        -sEXPORTED_FUNCTIONS=_WebPToSDL -sINVOKE_RUN=0 \
-       -sEXPORTED_RUNTIME_METHODS=cwrap")
+       -sEXPORTED_RUNTIME_METHODS=cwrap ${EMSCRIPTEN_SDL2_FLAGS} \
+       -sALLOW_MEMORY_GROWTH"
+  )
   target_compile_definitions(webp_wasm PUBLIC EMSCRIPTEN WEBP_HAVE_SDL)
 
   target_compile_definitions(webpdspdecode PUBLIC EMSCRIPTEN)
diff --git a/configure.ac b/configure.ac
index 2216e4a8..3933a6f0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -464,7 +464,7 @@ AC_ARG_ENABLE([sdl],
                               @<:@default=auto@:>@]))
 AS_IF([test "x$enable_sdl" != "xno"], [
   CLEAR_LIBVARS([SDL])
-  AC_PATH_PROGS([LIBSDL_CONFIG], [sdl-config])
+  AC_PATH_PROGS([LIBSDL_CONFIG], [sdl2-config])
   if test -n "$LIBSDL_CONFIG"; then
     SDL_INCLUDES=`$LIBSDL_CONFIG --cflags`
     SDL_LIBS="`$LIBSDL_CONFIG --libs`"
@@ -474,13 +474,12 @@ AS_IF([test "x$enable_sdl" != "xno"], [
 
   sdl_header="no"
   LIBCHECK_PROLOGUE([SDL])
-  AC_CHECK_HEADER([SDL/SDL.h], [sdl_header="SDL/SDL.h"],
-                  [AC_CHECK_HEADER([SDL.h], [sdl_header="SDL.h"],
-                  [AC_MSG_WARN(SDL library not available - no sdl.h)])])
+  AC_CHECK_HEADER([SDL2/SDL.h], [sdl_header="SDL2/SDL.h"],
+                  [AC_MSG_WARN(SDL2 library not available - no SDL.h)])
   if test x"$sdl_header" != "xno"; then
     AC_LANG_PUSH(C)
     SDL_SAVED_LIBS="$LIBS"
-    for lib in "" "-lSDL" "-lSDLmain -lSDL"; do
+    for lib in "" "-lSDL2" "-lSDL2main -lSDL2"; do
       LIBS="$SDL_SAVED_LIBS $lib"
       # Perform a full link to ensure SDL_main is resolved if needed.
       AC_LINK_IFELSE(
diff --git a/extras/vwebp_sdl.c b/extras/vwebp_sdl.c
index e9554eb1..acf48909 100644
--- a/extras/vwebp_sdl.c
+++ b/extras/vwebp_sdl.c
@@ -30,7 +30,7 @@
 #if defined(WEBP_HAVE_JUST_SDL_H)
 #include <SDL.h>
 #else
-#include <SDL/SDL.h>
+#include <SDL2/SDL.h>
 #endif
 
 static void ProcessEvents(void) {
diff --git a/extras/webp_to_sdl.c b/extras/webp_to_sdl.c
index 1e526811..971ffc88 100644
--- a/extras/webp_to_sdl.c
+++ b/extras/webp_to_sdl.c
@@ -20,88 +20,75 @@
 #include "webp_to_sdl.h"
 
 #include <stdio.h>
+
 #include "src/webp/decode.h"
 
 #if defined(WEBP_HAVE_JUST_SDL_H)
 #include <SDL.h>
 #else
-#include <SDL/SDL.h>
+#include <SDL2/SDL.h>
 #endif
 
 static int init_ok = 0;
 int WebPToSDL(const char* data, unsigned int data_size) {
   int ok = 0;
   VP8StatusCode status;
-  WebPDecoderConfig config;
-  WebPBitstreamFeatures* const input = &config.input;
-  WebPDecBuffer* const output = &config.output;
-  SDL_Surface* screen = NULL;
-  SDL_Surface* surface = NULL;
-
-  if (!WebPInitDecoderConfig(&config)) {
-    fprintf(stderr, "Library version mismatch!\n");
-    return 0;
-  }
+  WebPBitstreamFeatures input;
+  uint8_t* output = NULL;
+  SDL_Window* window = NULL;
+  SDL_Renderer* renderer = NULL;
+  SDL_Texture* texture = NULL;
+  int width, height;
 
   if (!init_ok) {
     SDL_Init(SDL_INIT_VIDEO);
     init_ok = 1;
   }
 
-  status = WebPGetFeatures((uint8_t*)data, (size_t)data_size, &config.input);
+  status = WebPGetFeatures((uint8_t*)data, (size_t)data_size, &input);
   if (status != VP8_STATUS_OK) goto Error;
+  width = input.width;
+  height = input.height;
 
-  screen = SDL_SetVideoMode(input->width, input->height, 32, SDL_SWSURFACE);
-  if (screen == NULL) {
-    fprintf(stderr, "Unable to set video mode (32bpp %dx%d)!\n",
-            input->width, input->height);
+  SDL_CreateWindowAndRenderer(width, height, 0, &window, &renderer);
+  if (window == NULL || renderer == NULL) {
+    fprintf(stderr, "Unable to create window or renderer!\n");
     goto Error;
   }
+  SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY,
+              "linear");  // make the scaled rendering look smoother.
+  SDL_RenderSetLogicalSize(renderer, width, height);
 
-  surface = SDL_CreateRGBSurface(SDL_SWSURFACE,
-                                 input->width, input->height, 32,
-                                 0x000000ffu,   // R mask
-                                 0x0000ff00u,   // G mask
-                                 0x00ff0000u,   // B mask
-                                 0xff000000u);  // A mask
-
-  if (surface == NULL) {
-    fprintf(stderr, "Unable to create %dx%d RGBA surface!\n",
-            input->width, input->height);
+  texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_ABGR8888,
+                              SDL_TEXTUREACCESS_STREAMING, width, height);
+  if (texture == NULL) {
+    fprintf(stderr, "Unable to create %dx%d RGBA texture!\n", width, height);
     goto Error;
   }
-  if (SDL_MUSTLOCK(surface)) SDL_LockSurface(surface);
 
 #if SDL_BYTEORDER == SDL_BIG_ENDIAN
-  output->colorspace = MODE_BGRA;
+  output = WebPDecodeBGRA((const uint8_t*)data, (size_t)data_size, &width,
+                          &height);
 #else
-  output->colorspace = MODE_RGBA;
+  output = WebPDecodeRGBA((const uint8_t*)data, (size_t)data_size, &width,
+                          &height);
 #endif
-  output->width  = surface->w;
-  output->height = surface->h;
-  output->u.RGBA.rgba   = surface->pixels;
-  output->u.RGBA.stride = surface->pitch;
-  output->u.RGBA.size   = surface->pitch * surface->h;
-  output->is_external_memory = 1;
-
-  status = WebPDecode((const uint8_t*)data, (size_t)data_size, &config);
-  if (status != VP8_STATUS_OK) {
+  if (output == NULL) {
     fprintf(stderr, "Error decoding image (%d)\n", status);
     goto Error;
   }
 
-  if (SDL_MUSTLOCK(surface)) SDL_UnlockSurface(surface);
-  if (SDL_BlitSurface(surface, NULL, screen, NULL) ||
-      SDL_Flip(screen)) {
-    goto Error;
-  }
-
+  SDL_UpdateTexture(texture, NULL, output, width * sizeof(uint32_t));
+  SDL_RenderClear(renderer);
+  SDL_RenderCopy(renderer, texture, NULL, NULL);
+  SDL_RenderPresent(renderer);
   ok = 1;
 
  Error:
-  SDL_FreeSurface(surface);
-  SDL_FreeSurface(screen);
-  WebPFreeDecBuffer(output);
+  // We should call SDL_DestroyWindow(window) but that makes .js fail.
+  SDL_DestroyRenderer(renderer);
+  SDL_DestroyTexture(texture);
+  WebPFree(output);
   return ok;
 }
 
diff --git a/makefile.unix b/makefile.unix
index 857ea988..428673a9 100644
--- a/makefile.unix
+++ b/makefile.unix
@@ -37,13 +37,13 @@ else
 endif
 
 # SDL flags: use sdl-config if it exists
-SDL_CONFIG = $(shell sdl-config --version 2> /dev/null)
+SDL_CONFIG = $(shell sdl2-config --version 2> /dev/null)
 ifneq ($(SDL_CONFIG),)
-  SDL_LIBS = $(shell sdl-config --libs)
-  SDL_FLAGS = $(shell sdl-config --cflags)
+  SDL_LIBS = $(shell sdl2-config --libs)
+  SDL_FLAGS = $(shell sdl2-config --cflags)
 else
   # use best-guess
-  SDL_LIBS = -lSDL
+  SDL_LIBS = -lSDL2
   SDL_FLAGS =
 endif
 
diff --git a/webp_js/README.md b/webp_js/README.md
index 824afa0b..ae9ce8f0 100644
--- a/webp_js/README.md
+++ b/webp_js/README.md
@@ -20,8 +20,7 @@ Emscripten and CMake.
 
     ```shell
     cd webp_js && \
-    emcmake cmake -DWEBP_BUILD_WEBP_JS=ON \
-          ../
+    emcmake cmake -DWEBP_BUILD_WEBP_JS=ON ../
     ```
 
 -   compile webp.js using 'emmake make'.
@@ -55,27 +54,7 @@ directory.
 See webp_js/index_wasm.html for a simple demo page using the WASM version of the
 library.
 
-You will need a fairly recent version of Emscripten (at least 2.0.18,
-latest-upstream is recommended) and of your WASM-enabled browser to run this
-version.
-
 ## Caveats
 
 -   First decoding using the library is usually slower, due to just-in-time
     compilation.
-
--   Some versions of llvm produce the following compile error when SSE2 is
-    enabled.
-
-    ```
-    "Unsupported:   %516 = bitcast <8 x i16> %481 to i128
-    LLVM ERROR: BitCast Instruction not yet supported for integer types larger than 64 bits"
-    ```
-
-    The corresponding Emscripten bug is at:
-    https://github.com/kripken/emscripten/issues/3788
-
-    Therefore, SSE2 optimization is currently disabled in CMakeLists.txt.
-
--   If WEBP_ENABLE_SIMD is set to 1 the JavaScript version (webp.js) will be
-    disabled as wasm2js does not support SIMD.
diff --git a/webp_js/index_wasm.html b/webp_js/index_wasm.html
index 5d7c17e8..7a9b362a 100644
--- a/webp_js/index_wasm.html
+++ b/webp_js/index_wasm.html
@@ -9,6 +9,7 @@
       noInitialRun : true
     };
   </script>
+  <script src="./webp_wasm.js"></script>
   <script type="text/javascript">
 
 'use strict';
@@ -16,40 +17,25 @@
 // main wrapper for the function decoding a WebP into a canvas object
 var WebpToCanvas;
 
-function init() {
-  var xhr = new XMLHttpRequest();
-  xhr.open('GET', 'webp_wasm.wasm', true);
-  xhr.responseType = 'arraybuffer';
-  xhr.onload = function() {
-    Module.wasmBinary = xhr.response;
-    var script = document.createElement('script');
-    script.src = "webp_wasm.js";
-    document.body.appendChild(script);
-  };
-  xhr.send(null);
-}
-window.onload = init;
+Module.onRuntimeInitialized = async () => {
+  // wrapper for the function decoding a WebP into a canvas object
+  WebpToCanvas = Module.cwrap('WebPToSDL', 'number', ['array', 'number']);
+};
 
 function decode(webp_data, canvas_id) {
   var result;
-  if (Module["asm"] != undefined) {
-    // wrapper for the function decoding a WebP into a canvas object
-    WebpToCanvas = Module.cwrap('WebPToSDL', 'number', ['array', 'number']);
-    // get the canvas to decode into
-    var canvas = document.getElementById(canvas_id);
-    if (canvas == null) return;
-    // clear previous picture (if any)
-    Module.canvas = canvas;
-    canvas.getContext('2d').clearRect(0, 0, canvas.width, canvas.height);
-    // decode and measure timing
-    var start = new Date();
-    var ret = WebpToCanvas(webp_data, webp_data.length);
-    var end = new Date();
-    var decode_time = end - start;
-    result = 'decoding time: ' + decode_time +' ms.';
-  } else {
-    result = "WASM module not finished loading! Please retry";
-  }
+  // get the canvas to decode into
+  var canvas = document.getElementById(canvas_id);
+  if (canvas == null) return;
+  // clear previous picture (if any)
+  Module.canvas = canvas;
+  canvas.getContext('2d').clearRect(0, 0, canvas.width, canvas.height);
+  // decode and measure timing
+  var start = new Date();
+  var ret = WebpToCanvas(webp_data, webp_data.length);
+  var end = new Date();
+  var decodeTime = end - start;
+  result = 'decoding time: ' + decodeTime +' ms.';
   // display timing result
   var speed_result = document.getElementById('timing');
   if (speed_result != null) {