How to find out Max Texture Size for WebGL on my system

I am working on an application where I apply filters on HD images using WebGL. The problem that I am facing is that when I apply the filters using WebGL image gets cut away which is because of the limitation on part of WebGL in my system.

So my question is How do i find out the max texture size of WebGL on my system. Currently I know for sure that its set to 2048. as the images of 2048 x 2048 work perfectly fine and images greater than that are causing issues.

Solution

The maximum texture size of a WebGLRenderingContext is returned by gl.getParameter(gl.MAX_TEXTURE_SIZE).
See the answer to the question "Is it possible to use WebGL max texture size?".

function getMaxTextureSize() {
    var gl = document.getElementById( "my-canvas").getContext( "experimental-webgl" );
    if ( !gl )
      return;
    document.getElementById( "textureSize" ).innerHTML = gl.getParameter(gl.MAX_TEXTURE_SIZE)
}

<body onload="getMaxTextureSize();">
    MAX_TEXTURE_SIZE : <span id="textureSize">0</span>
    <canvas id="my-canvas" style="border: none;" width="64" height="64"></canvas>
</body>