diff --git a/src/bindings/wasm/tvgWasm.cpp b/src/bindings/wasm/tvgWasm.cpp
index 924763a2..1a954423 100644
--- a/src/bindings/wasm/tvgWasm.cpp
+++ b/src/bindings/wasm/tvgWasm.cpp
@@ -220,7 +220,11 @@ public:
             return false;
         }
 
-        animation->picture()->size(width, height);
+        //keep the aspect ratio.
+        float ow, oh;
+        animation->picture()->size(&ow, &oh);
+        float scale =  static_cast<float>(width) / ow;
+        animation->picture()->size(ow * scale, oh * scale);
 
         auto saver = Saver::gen();
         if (!saver) {
diff --git a/src/tools/lottie2gif/lottie2gif.cpp b/src/tools/lottie2gif/lottie2gif.cpp
index 0d61c517..0d3ec398 100644
--- a/src/tools/lottie2gif/lottie2gif.cpp
+++ b/src/tools/lottie2gif/lottie2gif.cpp
@@ -72,7 +72,10 @@ private:
       auto picture = animation->picture();
       if (picture->load(in) != Result::Success) return false;
 
-      picture->size(static_cast<float>(width), static_cast<float>(height));
+      float width, height;
+      picture->size(&width, &height);
+      float scale =  static_cast<float>(this->width) / width;
+      picture->size(width * scale, height * scale);
 
       auto saver = Saver::gen();
       if (saver->save(std::move(animation), out, 100, fps) != Result::Success) return false;