Proper way to detect WebGL support?

Question

I am attempting to detect WebGL support across multiple browsers and I\'ve encountered the following scenario. The current version of Firefox appears to report positive supp

Answer 1

[Oct 2014] I've updated modernizrs example to match their current implementation, which is a cleaned up version from http://get.webgl.org/ further below.

Modernizr does,

var canvas;
var ctx;
var exts;

try {
  canvas = createElement('canvas');
  ctx = canvas.getContext('webgl') || canvas.getContext('experimental-webgl');
  exts = ctx.getSupportedExtensions();
}
catch (e) {
  return;
}

if (ctx !== undefined) {
  Modernizr.webglextensions = new Boolean(true);
}

for (var i = -1, len = exts.length; ++i < len; ){
  Modernizr.webglextensions[exts[i]] = true;
}

canvas = undefined;

Chromium points to http://get.webgl.org/ for the canonical support implementation,

try { gl = canvas.getContext("webgl"); }
catch (x) { gl = null; }

if (gl == null) {
    try { gl = canvas.getContext("experimental-webgl"); experimental = true; }
    catch (x) { gl = null; }
}