diff --git a/data/widgets/webp_options.xml b/data/widgets/webp_options.xml
new file mode 100644
index 000000000..2f9a9f698
--- /dev/null
+++ b/data/widgets/webp_options.xml
@@ -0,0 +1,48 @@
+<!-- ASEPRITE -->
+<!-- Copyright (C) 2014, 2015 by David Capello -->
+<gui>
+<window text="WebP Options" id="webp_options">
+  <vbox>
+    <label text="Save as:" />
+    <radio group="1" text="Lossless WebP" id="lossless" tooltip="Save in simple WebP lossless format." />
+    <hbox>
+      <label width="55" text="Compression:" />
+      <slider min="0" max="9" id="compression" cell_align="horizontal" width="128" />
+    </hbox>
+    <hbox>
+      <label width="55" text="Image Hint:" />
+      <combobox width="128" id="image_hint">
+        <listitem text="Default" value="0" />
+        <listitem text="Picture" value="1" />
+        <listitem text="Photo" value="2" />
+        <listitem text="Graph" value="3" />
+        <listitem text="Last" value="4" />
+      </combobox>
+    </hbox>
+    <separator horizontal="true" />
+    <radio group="1" text="Lossy WebP" id="lossy" tooltip="Save in simple WebP lossy format." />
+    <hbox>
+      <label width="55" text="Quality:" />
+      <slider min="0" max="100" id="quality" cell_align="horizontal" width="128" />
+    </hbox>
+    <hbox>
+      <label width="55" text="Image Preset:" />
+      <combobox width="128" id="image_preset">
+        <listitem text="Default" value="0" />
+        <listitem text="Picture" value="1" />
+        <listitem text="Photo" value="2" />
+        <listitem text="Drawing" value="3" />
+        <listitem text="Icon" value="4" />
+        <listitem text="Text" value="5" />
+      </combobox>
+    </hbox>
+    <hbox>
+      <boxfiller />
+      <hbox homogeneous="true">
+        <button text="&amp;OK" closewindow="true" id="ok" magnet="true" minwidth="60" />
+        <button text="&amp;Cancel" closewindow="true" />
+      </hbox>
+    </hbox>
+  </vbox>
+</window>
+</gui>
diff --git a/src/app/CMakeLists.txt b/src/app/CMakeLists.txt
index e070386ab..0125cdd46 100644
--- a/src/app/CMakeLists.txt
+++ b/src/app/CMakeLists.txt
@@ -274,6 +274,7 @@ add_library(app-lib
   file/png_format.cpp
   file/split_filename.cpp
   file/tga_format.cpp
+  file/webp_format.cpp
   file_selector.cpp
   file_system.cpp
   filename_formatter.cpp
@@ -412,6 +413,7 @@ target_link_libraries(app-lib
   ${JPEG_LIBRARIES}
   ${GIF_LIBRARIES}
   ${PNG_LIBRARIES}
+  ${WEBP_LIBRARIES}
   ${ZLIB_LIBRARIES})
 
 if(ENABLE_UPDATER)
diff --git a/src/app/file/file_formats_manager.cpp b/src/app/file/file_formats_manager.cpp
index 1a8f8027c..74b78e895 100644
--- a/src/app/file/file_formats_manager.cpp
+++ b/src/app/file/file_formats_manager.cpp
@@ -29,6 +29,7 @@ extern FileFormat* CreateJpegFormat();
 extern FileFormat* CreatePcxFormat();
 extern FileFormat* CreatePngFormat();
 extern FileFormat* CreateTgaFormat();
+extern FileFormat* CreateWebPFormat();
 
 static FileFormatsManager* singleton = NULL;
 
@@ -67,6 +68,7 @@ void FileFormatsManager::registerAllFormats()
   registerFormat(CreatePcxFormat());
   registerFormat(CreatePngFormat());
   registerFormat(CreateTgaFormat());
+  registerFormat(CreateWebPFormat());
 }
 
 void FileFormatsManager::registerFormat(FileFormat* fileFormat)
diff --git a/src/app/file/webp_format.cpp b/src/app/file/webp_format.cpp
new file mode 100644
index 000000000..489a4ceea
--- /dev/null
+++ b/src/app/file/webp_format.cpp
@@ -0,0 +1,361 @@
+// Aseprite
+// Copyright (C) 2001-2015  David Capello
+//
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License version 2 as
+// published by the Free Software Foundation.
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "app/app.h"
+#include "app/console.h"
+#include "app/context.h"
+#include "app/document.h"
+#include "app/file/file.h"
+#include "app/file/file_format.h"
+#include "app/file/format_options.h"
+#include "app/find_widget.h"
+#include "app/ini_file.h"
+#include "app/load_widget.h"
+#include "base/file_handle.h"
+#include "doc/doc.h"
+#include "ui/ui.h"
+
+#include <cstdio>
+#include <cstdlib>
+#include <algorithm>
+#include <map>
+
+
+//include webp librarys
+#include <webp/decode.h>
+#include <webp/encode.h>
+
+namespace app {
+
+using namespace base;
+
+class WebPFormat : public FileFormat {
+  // Data for WEBP files
+  class WebPOptions : public FormatOptions {
+  public:
+    WebPOptions(): lossless(0), quality(75), method(6), image_hint(WEBP_HINT_DEFAULT), image_preset(WEBP_PRESET_DEFAULT) {};
+    int lossless;           // Lossless encoding (0=lossy(default), 1=lossless).
+    float quality;          // between 0 (smallest file) and 100 (biggest)
+    int method;             // quality/speed trade-off (0=fast, 9=slower-better)
+    WebPImageHint image_hint;  // Hint for image type (lossless only for now).
+    WebPPreset image_preset;  // Image Preset for lossy webp.
+  };
+
+  const char* onGetName() const { return "webp"; }
+  const char* onGetExtensions() const { return "webp"; }
+  int onGetFlags() const {
+    return
+      FILE_SUPPORT_LOAD |
+      FILE_SUPPORT_SAVE |
+      FILE_SUPPORT_RGB |
+      FILE_SUPPORT_RGBA |
+      FILE_SUPPORT_SEQUENCES |
+      FILE_SUPPORT_GET_FORMAT_OPTIONS;
+  }
+
+  bool onLoad(FileOp* fop) override;
+#ifdef ENABLE_SAVE
+  bool onSave(FileOp* fop) override;
+#endif
+
+base::SharedPtr<FormatOptions> onGetFormatOptions(FileOp* fop) override;
+};
+
+FileFormat* CreateWebPFormat()
+{
+  return new WebPFormat;
+}
+
+const std::pair<VP8StatusCode, std::string> dec_error_map_data[] = {
+    std::make_pair(VP8_STATUS_OK, ""),
+    std::make_pair(VP8_STATUS_OUT_OF_MEMORY, "out of memory"),
+    std::make_pair(VP8_STATUS_INVALID_PARAM, "invalid parameters"),
+    std::make_pair(VP8_STATUS_BITSTREAM_ERROR, "bitstream error"),
+    std::make_pair(VP8_STATUS_UNSUPPORTED_FEATURE, "unsupported feature"),
+    std::make_pair(VP8_STATUS_SUSPENDED, "suspended"),
+    std::make_pair(VP8_STATUS_USER_ABORT, "user aborted"),
+    std::make_pair(VP8_STATUS_NOT_ENOUGH_DATA, "not enough data")
+};
+
+const std::map<VP8StatusCode, std::string> WebPDecodingErrorMap(dec_error_map_data, dec_error_map_data + sizeof dec_error_map_data / sizeof dec_error_map_data[0]);
+
+bool WebPFormat::onLoad(FileOp* fop)
+{
+  FileHandle handle(open_file_with_exception(fop->filename, "rb"));
+  FILE* fp = handle.get();
+
+  long len;
+	uint8_t* buf = NULL;
+
+  if (fseek(fp, 0, SEEK_END) != 0) {
+    fop_error(fop, "Error while getting WebP file size for %s\n", fop->filename.c_str());
+    return false;
+  }
+
+  len = ftell(fp);
+  rewind(fp);
+
+  if (len < 4) {
+    fop_error(fop, "%s is corrupt or not a WebP file\n", fop->filename.c_str());
+    return false;
+  }
+
+  buf = (uint8_t*) malloc(len);
+  if (!buf) {
+    fop_error(fop, "Error while allocating memory for %s\n", fop->filename.c_str());
+    return false;
+  }
+
+  if (!fread(buf, len, 1, fp)) {
+    fop_error(fop, "Error while writing to %s to memory\n", fop->filename.c_str());
+    free(buf);
+    return false;
+  }
+
+  WebPDecoderConfig config;
+  if (!WebPInitDecoderConfig(&config)) {
+    fop_error(fop, "LibWebP version mismatch %s\n", fop->filename.c_str());
+    free(buf);
+    return false;
+  }
+
+  if (WebPGetFeatures(buf, len, &config.input) != VP8_STATUS_OK) {
+    fop_error(fop, "Bad bitstream in %s\n", fop->filename.c_str());
+    free(buf);
+    return false;
+  }
+
+  fop->seq.has_alpha = config.input.has_alpha;
+  //TODO write imagefeatures
+
+  auto image = fop_sequence_image(fop, IMAGE_RGB, config.input.width, config.input.height);
+
+  config.output.colorspace = MODE_RGBA;
+  config.output.u.RGBA.rgba = (uint8_t*)image->getPixelAddress(0, 0);
+  config.output.u.RGBA.stride = config.input.width * sizeof(uint32_t);
+  config.output.u.RGBA.size = config.input.width * config.input.height * sizeof(uint32_t);
+  config.output.is_external_memory = 1;
+
+  WebPIDecoder* idec = WebPIDecode(NULL, 0, &config);
+  if (idec == NULL) {
+    fop_error(fop, "Error creating WebP decoder for %s\n", fop->filename.c_str());
+    free(buf);
+    return false;
+  }
+
+  auto bytes_remaining = len;
+  auto bytes_read = std::max(4l, len/100l);
+  auto data = buf;
+
+  while (bytes_remaining > 0) {
+    VP8StatusCode status = WebPIAppend(idec, data, bytes_read);
+    if (status == VP8_STATUS_OK || status == VP8_STATUS_SUSPENDED) {
+      bytes_remaining -= bytes_read;
+      data += bytes_read;
+      if (bytes_remaining < bytes_read) bytes_read = bytes_remaining;
+      fop_progress(fop, 1.0f - ((float)std::max(bytes_remaining, 0l)/(float)len));
+    } else {
+      fop_error(fop, "Error during decoding %s : %s\n", fop->filename.c_str(), WebPDecodingErrorMap.find(status)->second.c_str());
+      WebPIDelete(idec);
+      WebPFreeDecBuffer(&config.output);
+      free(buf);
+      return false;
+    }
+    if (fop_is_stop(fop))
+      break;
+  }
+  WebPIDelete(idec);
+  WebPFreeDecBuffer(&config.output);
+  return true;
+}
+
+#ifdef ENABLE_SAVE
+struct writerData {
+  FILE* fp;
+  FileOp* fop;
+};
+
+const std::pair<WebPEncodingError, std::string> enc_error_map_data[] = {
+    std::make_pair(VP8_ENC_OK, ""),
+    std::make_pair(VP8_ENC_ERROR_OUT_OF_MEMORY, "memory error allocating objects"),
+    std::make_pair(VP8_ENC_ERROR_BITSTREAM_OUT_OF_MEMORY, "memory error while flushing bits"),
+    std::make_pair(VP8_ENC_ERROR_NULL_PARAMETER, "a pointer parameter is NULL"),
+    std::make_pair(VP8_ENC_ERROR_INVALID_CONFIGURATION, "configuration is invalid"),
+    std::make_pair(VP8_ENC_ERROR_BAD_DIMENSION, "picture has invalid width/height"),
+    std::make_pair(VP8_ENC_ERROR_PARTITION0_OVERFLOW, "partition is bigger than 512k"),
+    std::make_pair(VP8_ENC_ERROR_PARTITION_OVERFLOW, "partition is bigger than 16M"),
+    std::make_pair(VP8_ENC_ERROR_BAD_WRITE, "error while flushing bytes"),
+    std::make_pair(VP8_ENC_ERROR_FILE_TOO_BIG, "file is bigger than 4G"),
+    std::make_pair(VP8_ENC_ERROR_OUT_OF_MEMORY, "memory error allocating objects"),
+    std::make_pair(VP8_ENC_ERROR_USER_ABORT, "abort request by user"),
+    std::make_pair(VP8_ENC_ERROR_LAST, "list terminator. always last.")
+};
+
+const std::map<WebPEncodingError, std::string> WebPEncodingErrorMap(enc_error_map_data, enc_error_map_data + sizeof enc_error_map_data / sizeof enc_error_map_data[0]);
+
+static int ProgressReport(int percent, const WebPPicture* const pic)
+{
+  fop_progress(((writerData*)pic->custom_ptr)->fop, (double)percent/(double)100);
+  if (fop_is_stop(((writerData*)pic->custom_ptr)->fop)) return false;
+  return true;
+}
+
+static int FileWriter(const uint8_t* data, size_t data_size, const WebPPicture* const pic)
+{
+  return data_size ? (fwrite(data, data_size, 1, ((writerData*)pic->custom_ptr)->fp) == 1) : 1;
+}
+
+
+//Helper functions instead of std::stoi because of missing c++11 on mac os x
+template<typename T>
+static inline std::string ToString(const T& v)
+{
+    std::ostringstream ss;
+    ss << v;
+    return ss.str();
+}
+
+template<typename T>
+static inline T FromString(const std::string& str)
+{
+    std::istringstream ss(str);
+    T ret;
+    ss >> ret;
+    return ret;
+}
+
+bool WebPFormat::onSave(FileOp* fop)
+{
+  FileHandle handle(open_file_with_exception(fop->filename, "wb"));
+  FILE* fp = handle.get();
+
+  struct writerData wd = {fp, fop};
+
+  auto image = fop->seq.image.get();
+  if (image->width() > WEBP_MAX_DIMENSION || image->height() > WEBP_MAX_DIMENSION) {
+   fop_error(
+     fop, "Error: WebP can only have a maximum width and height of %i but your %s has a size of %i x %i\n",
+     WEBP_MAX_DIMENSION, fop->filename.c_str(), image->width(), image->height()
+   );
+   return false;
+  }
+
+  base::SharedPtr<WebPOptions> webp_options = fop->seq.format_options;
+
+  WebPConfig config;
+
+  if (webp_options->lossless) {
+    if (!(WebPConfigInit(&config) && WebPConfigLosslessPreset(&config, webp_options->method))) {
+     fop_error(fop, "Error for WebP Config Version for file %s\n", fop->filename.c_str());
+     return false;
+    }
+    config.image_hint = webp_options->image_hint;
+  } else {
+    if (!WebPConfigPreset(&config, webp_options->image_preset, webp_options->quality)) {
+     fop_error(fop, "Error for WebP Config Version for file %s\n", fop->filename.c_str());
+     return false;
+    }
+  }
+
+  if (!WebPValidateConfig(&config)) {
+   fop_error(fop, "Error in WebP Encoder Config for file %s\n", fop->filename.c_str());
+   return false;
+  }
+
+  WebPPicture pic;
+  if (!WebPPictureInit(&pic)) {
+    fop_error(fop, "Error for WebP Picture Version mismatch for file %s\n", fop->filename.c_str());
+    return false;
+  }
+
+  pic.width = image->width();
+  pic.height = image->height();
+  if (webp_options->lossless) {
+    pic.use_argb = true;
+  }
+
+  if (!WebPPictureAlloc(&pic)) {
+    fop_error(fop, "Error for  WebP Picture memory allocations for file %s\n", fop->filename.c_str());
+    return false;
+  }
+
+  if (!WebPPictureImportRGBA(&pic, (uint8_t*)image->getPixelAddress(0, 0), image->width() * sizeof(uint32_t))) {
+    fop_error(fop, "Error for LibWebP Import RGBA Buffer into Picture for %s\n", fop->filename.c_str());
+    WebPPictureFree(&pic);
+    return false;
+  }
+
+  pic.writer = FileWriter;
+  pic.custom_ptr = &wd;
+  pic.progress_hook = ProgressReport;
+
+  if (!WebPEncode(&config, &pic)) {
+    fop_error(fop, "Error for LibWebP while Encoding %s: %s\n", fop->filename.c_str(), WebPEncodingErrorMap.find(pic.error_code)->second.c_str());
+    WebPPictureFree(&pic);
+    return false;
+  }
+
+  WebPPictureFree(&pic);
+  return true;
+}
+#endif
+
+// Shows the WebP configuration dialog.
+base::SharedPtr<FormatOptions> WebPFormat::onGetFormatOptions(FileOp* fop)
+{
+  base::SharedPtr<WebPOptions> webp_options;
+  if (fop->document->getFormatOptions())
+    webp_options = base::SharedPtr<WebPOptions>(fop->document->getFormatOptions());
+
+  if (!webp_options)
+    webp_options.reset(new WebPOptions);
+
+  // Non-interactive mode
+  if (!fop->context || !fop->context->isUIAvailable())
+    return webp_options;
+
+  try {
+
+    // Load the window to ask to the user the JPEG options he wants.
+    UniquePtr<ui::Window> window(app::load_widget<ui::Window>("webp_options.xml", "webp_options"));
+    ui::RadioButton* button_lossless = app::find_widget<ui::RadioButton>(window, "lossless");
+    ui::Slider* slider_compression = app::find_widget<ui::Slider>(window, "compression");
+    ui::Slider* slider_quality = app::find_widget<ui::Slider>(window, "quality");
+    ui::Widget* ok = app::find_widget<ui::Widget>(window, "ok");
+    ui::ComboBox* list_hint = app::find_widget<ui::ComboBox>(window, "image_hint");
+    ui::ComboBox* list_preset = app::find_widget<ui::ComboBox>(window, "image_preset");
+
+    button_lossless->setSelected(true);
+    slider_compression->setValue(6);
+    slider_quality->setValue(75);
+
+    window->openWindowInForeground();
+
+    if (window->getKiller() == ok) {
+      webp_options->quality = slider_quality->getValue();
+      webp_options->method = slider_compression->getValue();
+      webp_options->lossless = button_lossless->isSelected();
+      webp_options->image_hint = static_cast<WebPImageHint>(FromString<int>(list_hint->getValue()));
+      webp_options->image_preset = static_cast<WebPPreset>(FromString<int>(list_preset->getValue()));
+    }
+    else {
+      webp_options.reset(NULL);
+    }
+
+    return webp_options;
+  }
+  catch (std::exception& e) {
+    Console::showException(e);
+    return base::SharedPtr<WebPOptions>(0);
+  }
+}
+
+} // namespace app