diff --git a/lib/configuration.js b/lib/configuration.js
index f3187a3..2fbfacc 100644
--- a/lib/configuration.js
+++ b/lib/configuration.js
@@ -78,21 +78,47 @@ confProto.setOptions = function (options) {
 
 confProto.debug = false;
 
-confProto.setDebugLevel = function (level) {
-    var that = this;
+var _DEBUG_LEVEL_KEY = 'http2-cache.configuration._debugLevel',
+    _DEBUG_LEVEL_DEFAULT = false;
+
+confProto.setDebugLevel = function (debugLevel, persist) {
+
+    debugLevel = typeof debugLevel === 'string' ? debugLevel : debugLevel === true ? 'info' : null;
+
+    // Setter with persist but not 'auto'
+    if (debugLevel !== 'auto' && persist === true) {
 
-    level = typeof level === 'string' ? level : level === true ? 'info' : null;
+        _DEBUG_LEVEL_DEFAULT = debugLevel;
+
+        // Use localStorage if available
+        if (typeof localStorage !== 'undefined') {
+            localStorage.setItem(_DEBUG_LEVEL_KEY, _DEBUG_LEVEL_DEFAULT);
+        }
+
+    // Compute default value from store then const
+    } else if (debugLevel === 'auto') {
+
+        // Use localStorage if available
+        if (typeof localStorage !== 'undefined') {
+            debugLevel = localStorage.getItem(_DEBUG_LEVEL_KEY, _DEBUG_LEVEL_DEFAULT);
+        }
+
+        debugLevel = debugLevel || _DEBUG_LEVEL_DEFAULT;
+    }
 
     // Init debug/log
-    if (that._log && that._log.hasOwnProperty('debugLevel')) {
-        that._log.debugLevel = level;
+    if (this._log && this._log.hasOwnProperty('debugLevel')) {
+        this._log.debugLevel = debugLevel;
     }
-    
+
     // Sync current options value
-    that.options.debug = level;
+    this.options.debug = debugLevel;
 
     // Sync and cast has boolean
-    that.debug = !!that.options.debug; 
+    this.debug = !!debugLevel;
+
+    // Chainable
+    return this;
 };
 
 confProto.configuring = function () {
@@ -141,7 +167,8 @@ confProto.getTransport = function (url) {
         if (uri.protocol === 'ws:' || uri.protocol === 'wss:') {
             activeTransportConnections[uri.href] = websocket(uri.href, "h2", {
                 // TODO, maybe enable perMessageDeflate in production or on debug??
-                perMessageDeflate: that.debug === false
+                // Do perMessageDeflate false only on browser and if debug cause if make nodeJS spec fail
+                perMessageDeflate: typeof process !== 'undefined' || that.debug === false 
             });
 
         } else if(uri.protocol === 'tcp:') {
diff --git a/lib/http2-cache.js b/lib/http2-cache.js
index 747bde4..91dad5a 100644
--- a/lib/http2-cache.js
+++ b/lib/http2-cache.js
@@ -11,7 +11,7 @@
             enableXHROverH2 = require('./xhr.js').enableXHROverH2;
 
         enableXHROverH2(XMLHttpRequest, new Configuration({
-            debug: false // true='info' or (info|debug|trace)
+            debug: 'auto' // true='info' or (auto|info|debug|trace)
         }));
 
         // To update debug level after injection:
@@ -20,4 +20,7 @@
         //- XMLHttpRequest.configuration.setDebugLevel('trace');
     }
 
+    // To persit update debug level after injection:
+    //- XMLHttpRequest.configuration.setDebugLevel('debug', true);
+
 }(this));
diff --git a/lib/logger.js b/lib/logger.js
index 5206a6f..b958065 100644
--- a/lib/logger.js
+++ b/lib/logger.js
@@ -13,7 +13,8 @@ var defaultLogger = {
 };
 
 var consoleLogger = {
-  debugLevel: 'info', // 'info|debug|trace'
+  debugLevel: 'log', // 'log|debug|trace'
+  log: console.log,
   fatal: console.error,
   error: console.error,
   warn : console.warning || console.info,
@@ -37,24 +38,26 @@ var consoleLogger = {
       var args = (typeof ctx === 'string' ? [ctx, data] : arguments);
       debug.apply(console, args);
     } 
+    return this; 
   },
-  // Trace only
+  // Displayed when debugLevel is trace only
   trace: function (data, ctx) {
     var debug = console.debug || console.info;
     if (consoleLogger.debugLevel === 'trace') {
-      consoleLogger.debug(data, ctx);
+      return consoleLogger.debug(data, ctx);
     } 
+    return this; 
   },
   // Trace only
   child: function(msg) {
     if (consoleLogger.debugLevel === 'trace') {
-      console.info(msg);
+      return console.info(msg);
     } 
-  	return this; 
+    return this; 
   }
 };
 
 module.exports = {
-	consoleLogger: consoleLogger,
-	defaultLogger: defaultLogger
+  consoleLogger: consoleLogger,
+  defaultLogger: defaultLogger
 };
\ No newline at end of file