diff --git a/chrome/content/zotero/preferences/preferences.js b/chrome/content/zotero/preferences/preferences.js
index 56cc230006..49cbe2ecd5 100644
--- a/chrome/content/zotero/preferences/preferences.js
+++ b/chrome/content/zotero/preferences/preferences.js
@@ -26,6 +26,14 @@ var proxies;
 var charsets;
 var _io = {};
 
+
+var Zotero_Preferences = {
+
+	onClose: function () {
+		Zotero_Preferences.DebugOutput.onClose();
+	}
+}
+
 function init()
 {
 	// Display the appropriate modifier keys for the platform
@@ -40,6 +48,7 @@ function init()
 	populateQuickCopyList();
 	updateQuickCopyInstructions();
 	initSearchPane();
+	Zotero_Preferences.Debug_Output.init();
 	
 	var charsetMenu = document.getElementById("zotero-import-charsetMenu");
 	var charsetMap = Zotero_Charset_Menu.populate(charsetMenu, false);
@@ -1206,6 +1215,239 @@ function resetStyles() {
 }
 
 
+Zotero_Preferences.Debug_Output = {
+	_timer: null,
+	
+	init: function () {
+		var storing = Zotero.Debug.storing;
+		this._updateButton();
+		this.updateLines();
+		if (storing) {
+			this._initTimer();
+		}
+	},
+	
+	
+	toggleStore: function () {
+		var storing = Zotero.Debug.storing;
+		Zotero.Debug.setStore(!storing);
+		if (!storing) {
+			this._initTimer();
+		}
+		else {
+			if (this._timerID) {
+				this._timer.cancel();
+				this._timerID = null;
+			}
+		}
+		this._updateButton();
+		this.updateLines();
+	},
+	
+	
+	view: function () {
+		var uri = "zotero://debug/";
+		var features = "menubar=yes,toolbar=no,location=no,scrollbars,centerscreen,resizable";
+		
+		var wm = Components.classes["@mozilla.org/appshell/window-mediator;1"]
+		.getService(Components.interfaces.nsIWindowMediator);
+		var win = wm.getMostRecentWindow("navigator:browser");
+		if (win) {
+			win.open(uri, null, features);
+		}
+		else {
+			var ww = Components.classes["@mozilla.org/embedcomp/window-watcher;1"]
+						.getService(Components.interfaces.nsIWindowWatcher);
+			var win = ww.openWindow(null, uri, null, features + ",width=775,height=575", null);
+		}
+	},
+	
+	
+	// TODO: localize
+	submit: function () {
+		document.getElementById('debug-output-submit').disabled = true;
+		document.getElementById('debug-output-submit-progress').hidden = false;
+		
+		var url = "http://www.zotero.org/utils/dev/repo/report?debug=1";
+		var output = Zotero.Debug.get();
+		
+		var uploadCallback = function (xmlhttp) {
+			document.getElementById('debug-output-submit').disabled = false;
+			document.getElementById('debug-output-submit-progress').hidden = true;
+			
+			Zotero.debug(xmlhttp.responseText);
+			
+			var pr = Components.classes["@mozilla.org/network/default-prompt;1"]
+				.getService(Components.interfaces.nsIPrompt);
+			
+			if (!xmlhttp.responseXML) {
+				pr.alert(
+					Zotero.getString('general.error'),
+					'Invalid response from server'
+				);
+				return;
+			}
+			var reported = xmlhttp.responseXML.getElementsByTagName('reported');
+			if (reported.length != 1) {
+				pr.alert(
+					Zotero.getString('general.error'),
+					'The server returned an error. Please try again.'
+				);
+				return;
+			}
+			
+			var reportID = reported[0].getAttribute('reportID');
+			pr.alert(
+				"Submitted",
+				"Debug output has been sent to the Zotero server.\n\n"
+					+ "The Report ID is D" + reportID + "."
+			);
+		}
+		
+		var bufferUploader = function (data) {
+			var pr = Components.classes["@mozilla.org/network/default-prompt;1"]
+				.getService(Components.interfaces.nsIPrompt);
+			
+			var oldLen = output.length;
+			var newLen = data.length;
+			var savings = Math.round(((oldLen - newLen) / oldLen) * 100)
+			Zotero.debug("HTTP POST " + newLen + " bytes to " + url
+				+ " (gzipped from " + oldLen + " bytes; "
+				+ savings + "% savings)");
+			
+			if (Zotero.Utilities.HTTP.browserIsOffline()) {
+				pr.alert(
+					Zotero.getString(
+						'general.error',
+						Zotero.appName + " is in offline mode."
+					)
+				);
+				return false;
+			}
+			
+			var req =
+				Components.classes["@mozilla.org/xmlextras/xmlhttprequest;1"].
+					createInstance();
+			req.open('POST', url, true);
+			req.setRequestHeader('Content-Type', "application/octet-stream");
+			req.setRequestHeader('Content-Encoding', 'gzip');
+			
+			req.channel.notificationCallbacks = {
+				onProgress: function (request, context, progress, progressMax) {
+					var pm = document.getElementById('debug-output-submit-progress');
+					pm.mode = 'determined'
+					pm.value = progress;
+					pm.max = progressMax;
+				},
+				
+				// nsIInterfaceRequestor
+				getInterface: function (iid) {
+					try {
+						return this.QueryInterface(iid);
+					}
+					catch (e) {
+						throw Components.results.NS_NOINTERFACE;
+					}
+				},
+				
+				QueryInterface: function(iid) {
+					if (iid.equals(Components.interfaces.nsISupports) ||
+							iid.equals(Components.interfaces.nsIInterfaceRequestor) ||
+							iid.equals(Components.interfaces.nsIProgressEventSink)) {
+						return this;
+					}
+					throw Components.results.NS_NOINTERFACE;
+				},
+
+			}
+			req.onreadystatechange = function () {
+				if (req.readyState == 4) {
+					uploadCallback(req);
+				}
+			};
+			try {
+				req.sendAsBinary(data);
+			}
+			catch (e) {
+				pr.alert(
+					Zotero.getString('general.error'),
+					"An error occurred sending debug output."
+				);
+			}
+		}
+		
+		// Get input stream from debug output data
+		var unicodeConverter =
+			Components.classes["@mozilla.org/intl/scriptableunicodeconverter"]
+				.createInstance(Components.interfaces.nsIScriptableUnicodeConverter);
+		unicodeConverter.charset = "UTF-8";
+		var bodyStream = unicodeConverter.convertToInputStream(output);
+		
+		// Get listener for when compression is done
+		var listener = new Zotero.BufferedInputListener(bufferUploader);
+		
+		// Initialize stream converter
+		var converter =
+			Components.classes["@mozilla.org/streamconv;1?from=uncompressed&to=gzip"]
+				.createInstance(Components.interfaces.nsIStreamConverter);
+		converter.asyncConvertData("uncompressed", "gzip", listener, null);
+		
+		// Send input stream to stream converter
+		var pump = Components.classes["@mozilla.org/network/input-stream-pump;1"].
+				createInstance(Components.interfaces.nsIInputStreamPump);
+		pump.init(bodyStream, -1, -1, 0, 0, true);
+		pump.asyncRead(converter, null);
+	},
+	
+	
+	clear: function () {
+		Zotero.Debug.clear();
+		this.updateLines();
+	},
+	
+	
+	updateLines: function () {
+		var lines = Zotero.Debug.count();
+		document.getElementById('debug-output-lines').value = lines;
+		var empty = lines == 0;
+		document.getElementById('debug-output-view').disabled = empty;
+		document.getElementById('debug-output-clear').disabled = empty;
+		document.getElementById('debug-output-submit').disabled = empty;
+	},
+	
+	
+	_initTimer: function () {
+		this._timer = Components.classes["@mozilla.org/timer;1"].
+			createInstance(Components.interfaces.nsITimer);
+		this._timer.initWithCallback({
+			notify: function() {
+				Zotero_Preferences.Debug_Output.updateLines();
+			}
+		}, 10000, Components.interfaces.nsITimer.TYPE_REPEATING_SLACK);
+	},
+	
+	
+	_updateButton: function () {
+		var storing = Zotero.Debug.storing
+		
+		var button = document.getElementById('debug-output-enable');
+		// TODO: localize
+		if (storing) {
+			button.label = "Disable";
+		}
+		else {
+			button.label = "Enable";
+		}
+	},
+	
+	
+	onClose: function () {
+		if (this._timer) {
+			this._timer.cancel();
+		}
+	}
+}
+
 function onOpenURLSelected()
 {
 	var openURLMenu = document.getElementById('openURLMenu');
diff --git a/chrome/content/zotero/preferences/preferences.xul b/chrome/content/zotero/preferences/preferences.xul
index a95707994b..e9176bd068 100644
--- a/chrome/content/zotero/preferences/preferences.xul
+++ b/chrome/content/zotero/preferences/preferences.xul
@@ -37,8 +37,9 @@ To add a new preference:
 		in Zotero.Prefs.observe()
 
 -->
-<prefwindow id="zotero-prefs" title="&zotero.preferences.title;" onload="moveToAlertPosition(); init()"
-		windowtype="zotero:pref" xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
+<prefwindow id="zotero-prefs" title="&zotero.preferences.title;" onload="moveToAlertPosition(); init()" onclose="Zotero_Preferences.onClose()"
+		windowtype="zotero:pref" xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
+		>
 	
 	<prefpane id="zotero-prefpane-general"
 						label="&zotero.preferences.prefpane.general;"
@@ -724,6 +725,7 @@ To add a new preference:
 			<preference id="pref-useDataDir" name="extensions.zotero.useDataDir" type="bool"/>
 			<preference id="pref-dataDir" name="extensions.zotero.dataDir" type="string"/>
 			<preference id="pref-export-displayCharsetOption" name="extensions.zotero.export.displayCharsetOption" type="bool"/>
+			<preference id="pref-debug-output-enableAfterRestart" name="extensions.zotero.debug.store" type="bool"/>
 			<preference id="pref-import-charset" name="extensions.zotero.import.charset" type="string"/>
 		</preferences>
 		
@@ -756,6 +758,30 @@ To add a new preference:
 			</hbox>
 		</groupbox>
 		
+		<groupbox>
+			<!-- TODO: localize -->
+			<caption label="Debug Output Logging"/>
+			
+			<!-- This doesn't wrap without an explicit width -->
+			<vbox>
+				<description width="45em">Debug output can help Zotero developers diagnose problems in Zotero. Debug logging will slow down Zotero, so you should generally leave it disabled unless a Zotero developer requests debug output.</description>
+			</vbox>
+			
+			<hbox align="center">
+				<button id="debug-output-enable" oncommand="Zotero_Preferences.Debug_Output.toggleStore()"/>
+				<label id="debug-output-lines" style="margin-right: 0"/>
+				<label value="lines logged"/>
+				<checkbox preference="pref-debug-output-enableAfterRestart" label="Enable after restart" style="margin-left: 1.5em"/>
+			</hbox>
+			
+			<hbox align="center">
+				<button id="debug-output-view" label="View Output" oncommand="Zotero_Preferences.Debug_Output.view()"/>
+				<button id="debug-output-clear" label="Clear Output" oncommand="Zotero_Preferences.Debug_Output.clear()"/>
+				<button id="debug-output-submit" label="Submit to Zotero Server" oncommand="Zotero_Preferences.Debug_Output.submit()"/>
+				<progressmeter id="debug-output-submit-progress" mode="undetermined" hidden="true"/>
+			</hbox>
+		</groupbox>
+		
 		<groupbox>
 			<caption label="&zotero.preferences.charset;"/>
 			
diff --git a/chrome/content/zotero/xpcom/debug.js b/chrome/content/zotero/xpcom/debug.js
new file mode 100644
index 0000000000..24e6446c5f
--- /dev/null
+++ b/chrome/content/zotero/xpcom/debug.js
@@ -0,0 +1,91 @@
+// TODO: license
+
+Zotero.Debug = new function () {
+	this.__defineGetter__('storing', function () _store);
+	
+	var _console;
+	var _store;
+	var _level;
+	var _time;
+	var _lastTime;
+	var _output = [];
+	
+	
+	this.init = function () {
+		_console = Zotero.Prefs.get('debug.log');
+		_store = Zotero.Prefs.get('debug.store');
+		_level = Zotero.Prefs.get('debug.level');
+		_time = Zotero.Prefs.get('debug.time');
+	}
+	
+	this.log = function (message, level) {
+		if (!_console && !_store) {
+			return;
+		}
+		
+		if (typeof message != 'string') {
+			message = Zotero.varDump(message);
+		}
+		
+		if (!level) {
+			level = 3;
+		}
+		
+		// If level above debug.level value, don't display
+		if (level > _level) {
+			return;
+		}
+		
+		var deltaStr = '';
+		if (_time || _store) {
+			var delta = 0;
+			var d = new Date();
+			if (_lastTime) {
+				delta = d - _lastTime;
+			}
+			_lastTime = d;
+			
+			while (("" + delta).length < 7) {
+				delta = '0' + delta;
+			}
+			
+			deltaStr = '(+' + delta + ')';
+		}
+		
+		if (_console) {
+			dump('zotero(' + level + ')' + (_time ? deltaStr : '') + ': ' + message + "\n\n");
+		}
+		if (_store) {
+			if (Zotero.Utilities.prototype.probability(1000)) {
+				// Remove initial lines if over limit
+				var overage = this.count() - Zotero.Prefs.get('debug.store.limit');
+				if (overage > 0) {
+					_output.splice(0, Math.abs(overage));
+				}
+			}
+			_output.push('(' + level + ')' + deltaStr + ': ' + message);
+		}
+	}
+	
+	this.get = function () {
+		return _output.join('\n\n');
+	}
+	
+	
+	this.setStore = function (enable) {
+		if (enable) {
+			this.clear();
+		}
+		_store = enable;
+	}
+	
+	
+	this.count = function () {
+		return _output.length;
+	}
+	
+	
+	this.clear = function () {
+		_output = [];
+	}
+}
diff --git a/chrome/content/zotero/xpcom/zotero.js b/chrome/content/zotero/xpcom/zotero.js
index 4041b1739f..ab3018e1f0 100644
--- a/chrome/content/zotero/xpcom/zotero.js
+++ b/chrome/content/zotero/xpcom/zotero.js
@@ -135,10 +135,6 @@ var Zotero = new function(){
 	var _startupError;
 	var _startupErrorHandler;
 	var _zoteroDirectory = false;
-	var _debugLogging;
-	var _debugLevel;
-	var _debugTime;
-	var _debugLastTime;
 	var _localizedStringBundle;
 	var _localUserKey;
 	var _waiting;
@@ -167,9 +163,7 @@ var Zotero = new function(){
 		// Load in the preferences branch for the extension
 		Zotero.Prefs.init();
 		
-		_debugLogging = Zotero.Prefs.get('debug.log');
-		_debugLevel = Zotero.Prefs.get('debug.level');
-		_debugTime = Zotero.Prefs.get('debug.time');
+		Zotero.Debug.init();
 		
 		this.mainThread = Components.classes["@mozilla.org/thread-manager;1"].getService().mainThread;
 		
@@ -606,41 +600,7 @@ var Zotero = new function(){
 	 * Defaults to log level 3 if level not provided
 	 */
 	function debug(message, level) {
-		if (!_debugLogging){
-			return false;
-		}
-		
-		if (typeof message!='string'){
-			message = Zotero.varDump(message);
-		}
-		
-		if (!level){
-			level = 3;
-		}
-		
-		// If level above debug.level value, don't display
-		if (level > _debugLevel){
-			return false;
-		}
-		
-		var deltaStr = '';
-		if (_debugTime) {
-			var delta = 0;
-			var d = new Date();
-			if (_debugLastTime) {
-				delta = d - _debugLastTime;
-			}
-			_debugLastTime = d;
-			
-			while (("" + delta).length < 7) {
-				delta = '0' + delta;
-			}
-			
-			deltaStr = '(+' + delta + ')';
-		}
-		
-		dump('zotero(' + level + ')' + deltaStr + ': ' + message + "\n\n");
-		return true;
+		Zotero.Debug.log(message, level);
 	}
 	
 	
diff --git a/components/zotero-protocol-handler.js b/components/zotero-protocol-handler.js
index dfa63f7227..1401483c8f 100644
--- a/components/zotero-protocol-handler.js
+++ b/components/zotero-protocol-handler.js
@@ -808,11 +808,42 @@ function ChromeExtensionHandler() {
 			}
 		}
 	};
-
+	
+	
+	/*
+		zotero://debug/
+	*/
+	var DebugExtension = new function() {
+		this.newChannel = newChannel;
+		
+		this.__defineGetter__('loadAsChrome', function () { return false; });
+		
+		function newChannel(uri) {
+			var ioService = Components.classes["@mozilla.org/network/io-service;1"]
+				.getService(Components.interfaces.nsIIOService);
+			
+			var Zotero = Components.classes["@zotero.org/Zotero;1"]
+				.getService(Components.interfaces.nsISupports)
+				.wrappedJSObject;
+			
+			try {
+				var output = Zotero.Debug.get();
+				
+				var uriStr = 'data:text/plain,' + encodeURIComponent(output);
+				var extURI = ioService.newURI(uriStr, null, null);
+				return ioService.newChannelFromURI(extURI);
+			}
+			catch (e) {
+				Zotero.debug(e);
+				throw (e);
+			}
+		}
+	};
+	
 	
 	var ReportExtensionSpec = ZOTERO_SCHEME + "://report"
 	this._extensions[ReportExtensionSpec] = ReportExtension;
-
+	
 	var TimelineExtensionSpec = ZOTERO_SCHEME + "://timeline"
 	this._extensions[TimelineExtensionSpec] = TimelineExtension;
 	
@@ -824,6 +855,9 @@ function ChromeExtensionHandler() {
 	
 	var FullscreenExtensionSpec = ZOTERO_SCHEME + "://fullscreen"
 	this._extensions[FullscreenExtensionSpec] = FullscreenExtension;
+	
+	var DebugExtensionSpec = ZOTERO_SCHEME + "://debug"
+	this._extensions[DebugExtensionSpec] = DebugExtension;
 }
 
 
diff --git a/components/zotero-service.js b/components/zotero-service.js
index 7a1d52be80..5cb2b8d689 100644
--- a/components/zotero-service.js
+++ b/components/zotero-service.js
@@ -40,6 +40,7 @@ var xpcomFiles = [
 	'data/tag',
 	'data/tags',
 	'db',
+	'debug',
 	'duplicate',
 	'enstyle',
 	'error',
diff --git a/defaults/preferences/zotero.js b/defaults/preferences/zotero.js
index d07101fc21..bb3a0bc4ca 100644
--- a/defaults/preferences/zotero.js
+++ b/defaults/preferences/zotero.js
@@ -11,6 +11,8 @@ pref("extensions.zotero.dataDir", '');
 pref("extensions.zotero.lastDataDir", '');
 pref("extensions.zotero.dbLockExclusive", true);
 pref("extensions.zotero.debug.log",false);
+pref("extensions.zotero.debug.store",false);
+pref("extensions.zotero.debug.store.limit",750000);
 pref("extensions.zotero.debug.level",5);
 pref("extensions.zotero.debug.time", false);
 pref("extensions.zotero.automaticScraperUpdates",true);