Problem with size of gltf with animation

Hello. I am trying to create low recource model. And I found very strange thing with size of file:
I imported Flamingo.glb (76 kb) from three js exaples. Then I just exported it to f.glb and got 610 kb size.
When I remove flag “export animation”, I got 68 kb. When I put some more animations - size became 5 Mb.

Is threre a way to make low recource models with animations using blender (latest version)?

This question has, hopefully, been answered in https://github.com/KhronosGroup/glTF-Blender-IO/issues/1322. Exporting from Blender includes vertex normals by default, and the original model did not use vertex normals. In this case that also requires increasing the vertex count, which increased the size. Vertex normals can be disabled in the export settings to keep the original file size.

Thank you very much for help. Model with animation became even lesser (72 kb) than source (76 kb).