Utilize the new PerformanceResourceTiming specification in order to figure out programmatically which resources in your website are misnamed by case only. This can help reduce redundant requests. This is a first crack at the API and only limited testing has been done. There may be URL canonicalization steps that could be made and restriction of …

ResourceTimingArbiter.js

"use strict";

Object.defineProperties(this, {
  "ResourceTimingArbiter": {
		value: (function () {
			var _oldResources = [];
			var _allDupes = [];
			var _resourceArbiter = {};
			var _escape = function(str) {
				return "".replace.call(str, /[-[\]{}()*+?.,\\^$|#\s]/g, "\\$&");
			};

			var _processDupes = function processDupes(checkSet, baseSet) {
				var dupes = [];
				for(var baseIndex = 0; baseIndex < baseSet.length; baseIndex++) {
					var resourceTiming = baseSet[baseIndex];
					if (!resourceTiming._ciRegex) {
						resourceTiming._ciRegex = new RegExp("^" + _escape(resourceTiming.name) + "$", "i");
					}

					for(var checkIndex = 0; checkIndex < checkSet.length; checkIndex++) {
						var checkTiming = checkSet[checkIndex];
						if (checkTiming !== resourceTiming && !checkTiming.dupedTo && resourceTiming._ciRegex.test(checkTiming.name)) {
							checkTiming.dupedTo = resourceTiming;
							_allDupes.push(checkTiming);
						}
					}
				}
				return dupes;
			}

			if (typeof(PerformanceResourceTiming) !== "undefined") {
				Object.defineProperties(_resourceArbiter, {
					getDuplicateResources: {
						value: function getDuplicateResources() {
							var newResources = performance.getEntriesByType("resource");
							performance.clearResourceTimings();

							_processDupes(newResources, newResources);
							_processDupes(newResources, _oldResources);

							_oldResources = _oldResources.concat(newResources);
							return _allDupes.map(function (elem) { return elem; });
						}
					},
					dumpAllResourcesToConsole: {
						value: function dumpAllResourcesToConsole() {
							// Ensure all resources are in _oldResources;
							this.getDuplicateResources();


							for(var resIndex = 0; resIndex < _oldResources.length; resIndex++) {
								var resourceTiming = _oldResources[resIndex];
								window.console.log("Resource: ", resourceTiming.name);
								window.console.log("\tInitiator: ", resourceTiming.initiatorType);
								window.console.log("\tDuplicate: ", (resourceTiming.dupedTo !== undefined));
							}
						}
					},
					dumpAllDupesToConsole: {
						value: function dumpAllDupesToConsole() {
							var allDupes = this.getDuplicateResources();
							for(var dupeIndex = 0; dupeIndex < allDupes.length; dupeIndex++) {
								var dupe = allDupes[dupeIndex];
								window.console.log("Duplicate resource: ", dupe.name, " --> ", dupe.dupedTo.name);
							}
						}
					},
					isSupported: {
						value: true
					}
				});
			}
			else {
				Object.defineProperties(_resourceArbiter, {
					isSupported: {
						value: false
					}
				});
			}

			return _resourceArbiter;
		})()
	}
});