diff --git a/advagg.advagg.inc b/advagg.advagg.inc
index 0bb690e..95ca3f5 100644
--- a/advagg.advagg.inc
+++ b/advagg.advagg.inc
@@ -16,8 +16,10 @@
  *   array($uri => $contents)
  * @param $aggregate_settings
  *   array of settings.
+ * @param $other_parameters
+ *   array of containing $files & $type.
  */
-function advagg_advagg_save_aggregate_alter(&$files_to_save, $aggregate_settings) {
+function advagg_advagg_save_aggregate_alter(&$files_to_save, $aggregate_settings, $other_parameters) {
   // Return if gzip is disabled.
   if (empty($aggregate_settings['variables']['advagg_gzip'])) {
     return;
diff --git a/advagg.cache.inc b/advagg.cache.inc
index 0e3e86e..c52f578 100644
--- a/advagg.cache.inc
+++ b/advagg.cache.inc
@@ -95,6 +95,10 @@ function advagg_push_new_changes() {
       advagg_insert_update_files(array($filename => $meta_data), $ext);
     }
 
+    // Let other modules know about the changed files.
+    // Call hook_advagg_changed_files().
+    module_invoke_all('advagg_changed_files', $files, $types);
+
     // Clear out the full aggregates cache.
     foreach ($types as $ext => $bool) {
       cache_clear_all('advagg:' . $ext . ':', 'cache_advagg_aggregates', TRUE);
diff --git a/advagg.inc b/advagg.inc
index 8266bf6..2deb20e 100644
--- a/advagg.inc
+++ b/advagg.inc
@@ -332,11 +332,23 @@ function advagg_get_aggregate_info_from_files($type, $files) {
  */
 function advagg_get_info_on_file($filename, $bypass_cache = FALSE) {
   $filename_hash = drupal_hash_base64($filename);
+  $filename_hashes = &drupal_static('advagg_get_info_on_file');
 
   // Use caching to avoid hitting disk if possible.
   $cache_id = 'advagg:file:' . $filename_hash;
-  if (!$bypass_cache && variable_get('advagg_use_file_cache', ADVAGG_USE_FILE_CACHE) && $cache = cache_get($cache_id, 'cache_advagg_info')) {
-    return $cache->data;
+  if (!$bypass_cache) {
+    // Try static cache first.
+    if (   !empty($filename_hashes)
+        && array_key_exists($cache_id, $filename_hashes)
+        && !empty($filename_hashes[$cache_id])
+          ) {
+      return $filename_hashes[$cache_id];
+    }
+
+    // Try cache backend next.
+    if (variable_get('advagg_use_file_cache', ADVAGG_USE_FILE_CACHE) && $cache = cache_get($cache_id, 'cache_advagg_info')) {
+      return $cache->data;
+    }
   }
 
   // Clear PHP's internal file status cache.
@@ -355,7 +367,7 @@ function advagg_get_info_on_file($filename, $bypass_cache = FALSE) {
   $linecount = substr_count($file_contents, "\n");
 
   // Build meta data array and set cache.
-  $data = array(
+  $filename_hashes[$cache_id] = array(
     'filesize' => filesize($filename),
     'mtime' => @filemtime($filename),
     'filename_hash' => $filename_hash,
@@ -363,9 +375,9 @@ function advagg_get_info_on_file($filename, $bypass_cache = FALSE) {
     'linecount' => $linecount,
   );
   if (variable_get('advagg_use_file_cache', ADVAGG_USE_FILE_CACHE)) {
-    cache_set($cache_id, $data, 'cache_advagg_info', CACHE_PERMANENT);
+    cache_set($cache_id, $filename_hashes[$cache_id], 'cache_advagg_info', CACHE_PERMANENT);
   }
-  return $data;
+  return $filename_hashes[$cache_id];
 }
 
 /**
diff --git a/advagg.missing.inc b/advagg.missing.inc
index 7f03b4b..06adb5e 100644
--- a/advagg.missing.inc
+++ b/advagg.missing.inc
@@ -438,9 +438,9 @@ function advagg_save_aggregate($filename, $files, $type, $aggregate_settings) {
     $uri => $contents,
   );
 
-  // Allow other modules to alter the contents and add new files to save.
+  // Allow other modules to alter the contents and add new files to save (.gz).
   // Call hook_advagg_save_aggregate_alter().
-  drupal_alter('advagg_save_aggregate', $files_to_save, $aggregate_settings);
+  drupal_alter('advagg_save_aggregate', $files_to_save, $aggregate_settings, array($files, $type));
 
   foreach ($files_to_save as $uri => $data) {
     advagg_save_data($uri, $data);
diff --git a/advagg.module b/advagg.module
index cc92ffb..63fb14e 100644
--- a/advagg.module
+++ b/advagg.module
@@ -59,6 +59,7 @@ function advagg_hook_info() {
     'advagg_get_js_aggregate_contents_alter',
     'advagg_save_aggregate_alter',
     'advagg_build_aggregate_plans_alter',
+    'advagg_changed_files',
   );
   $hooks = array();
   foreach ($advagg_hooks as $hook) {
@@ -784,6 +785,7 @@ function advagg_hooks_implemented($all = TRUE) {
   if ($all) {
     $hooks += array(
       'advagg_build_aggregate_plans_alter' => array(),
+      'advagg_changed_files' => array(),
       'js_alter' => array(),
       'css_alter' => array(),
     );
diff --git a/advagg_js_compress/advagg_js_compress.advagg.inc b/advagg_js_compress/advagg_js_compress.advagg.inc
index 5eb90f5..f35ed23 100644
--- a/advagg_js_compress/advagg_js_compress.advagg.inc
+++ b/advagg_js_compress/advagg_js_compress.advagg.inc
@@ -25,8 +25,16 @@ function advagg_js_compress_advagg_get_js_file_contents_alter(&$contents, $filen
  *   array($uri => $contents)
  * @param $aggregate_settings
  *   array of settings.
+ * @param $other_parameters
+ *   array of containing $files & $type.
  */
-function advagg_js_compress_advagg_save_aggregate_alter(&$files_to_save, $aggregate_settings) {
+function advagg_js_compress_advagg_save_aggregate_alter(&$files_to_save, $aggregate_settings, $other_parameters) {
+  list($files, $type) = $other_parameters;
+
+  // Return if type is not js.
+  if ($type != 'js') {
+    return;
+  }
   // Return if gzip is disabled.
   if (empty($aggregate_settings['variables']['advagg_gzip'])) {
     return;
@@ -35,6 +43,10 @@ function advagg_js_compress_advagg_save_aggregate_alter(&$files_to_save, $aggreg
   if (empty($aggregate_settings['variables']['advagg_js_compress_packer'])) {
     return;
   }
+  // Make sure all files in this aggregrate are compatible with packer.
+  foreach ($files as $file) {
+
+  }
 
   // See if a .gz file already exists.
   $gzip_exists = FALSE;
@@ -63,46 +75,94 @@ function advagg_js_compress_advagg_save_aggregate_alter(&$files_to_save, $aggreg
   }
 
   // Use packer on non gzip JS data.
-  advagg_js_compress_jspacker($data);
+  $aggregate_settings['variables']['advagg_js_compressor'] = 2;
+  advagg_js_compress_prep($data, $uri, $aggregate_settings, FALSE);
   $files_to_save[$uri] = $data;
 }
 
 /**
+ * Implement advagg_changed_files().
+ */
+function advagg_js_compress_advagg_changed_files($files, $types) {
+  // Only care about js files.
+  if (empty($types['js'])) {
+    return;
+  }
+  $return = array();
+  foreach ($files as $filename => $meta_data) {
+    // Only care about js files.
+    $ext = pathinfo($filename, PATHINFO_EXTENSION);
+    if ($ext != 'js') {
+      continue;
+    }
+
+    $compressors = array(0 => 'jsminplus', 2 => 'packer');
+    if (function_exists('jsmin')) {
+      $compressors[1] = 'jsmin';
+      ksort($compressors);
+    }
+
+    $return[$filename] = advagg_js_compress_run_test($filename);
+  }
+  return $return;
+}
+
+/**
  * Compress a JS string
  *
  * @param $contents
  *   Javascript string.
  * @param $filename
  *   filename.
+ * @param $add_licensing
+ *   FALSE to remove Source and licensing information comment.
+ * @param $log_errors
+ *   FALSE to disable logging to watchdog on failure.
+ * @param $test_ratios
+ *   FALSE to disable compression ratio testing.
  */
-function advagg_js_compress_prep(&$contents, $filename, $aggregate_settings) {
+function advagg_js_compress_prep(&$contents, $filename, $aggregate_settings, $add_licensing = TRUE, $log_errors = TRUE, $test_ratios = TRUE) {
+  // Get the info on this file.
+  module_load_include('inc', 'advagg', 'advagg');
+  $info = advagg_get_info_on_file($filename);
+  $compressor = $aggregate_settings['variables']['advagg_js_compressor'];
+
+
+
   // Get the JS string length before the compression operation.
   $contents_before = $contents;
   $before = strlen($contents);
 
+  // Strip Byte Order Marks (BOM's) from the file, preg_* cannot parse these.
+  $contents = str_replace(pack("CCC", 0xef, 0xbb, 0xbf), "", $contents);
+
   // Use the compressor.
-  $compressor = $aggregate_settings['variables']['advagg_js_compressor'];
   if ($compressor == 0) {
-    advagg_js_compress_jsminplus($contents);
+    advagg_js_compress_jsminplus($contents, $log_errors);
   }
   elseif ($compressor == 1) {
     $contents = jsmin($contents);
   }
-
-  // Make sure compression ratios are good.
-  $after = strlen($contents);
-  $ratio = 0;
-  if ($before != 0) {
-    $ratio = ($before - $after) / $before;
-  }
-  // Make sure the returned string is not empty or has a VERY high
-  // compression ratio.
-  if (empty($contents) || empty($ratio) || $ratio > $aggregate_settings['variables']['advagg_js_max_compress_ratio']) {
-    $contents = $contents_before;
+  elseif ($compressor == 2) {
+    advagg_js_compress_jspacker($contents);
   }
-  else {
-    $url = url($filename, array('absolute' => TRUE));
-    $contents = "/* Source and licensing information for the line(s) below can be found at $url. */\n" . $contents . ";\n/* Source and licensing information for the above line(s) can be found at $url. */\n";
+
+  if ($test_ratios) {
+    // Make sure compression ratios are good.
+    $after = strlen($contents);
+    $ratio = 0;
+    if ($before != 0) {
+      $ratio = ($before - $after) / $before;
+    }
+    // Make sure the returned string is not empty or has a VERY high
+    // compression ratio.
+    if (empty($contents) || empty($ratio) || $ratio > $aggregate_settings['variables']['advagg_js_max_compress_ratio']) {
+      $contents = $contents_before;
+    }
+    elseif ($add_licensing) {
+      $url = url($filename, array('absolute' => TRUE));
+      $contents = "/* Source and licensing information for the line(s) below can be found at $url. */\n" . $contents . ";\n/* Source and licensing information for the above line(s) can be found at $url. */\n";
+    }
   }
 }
 
@@ -111,10 +171,10 @@ function advagg_js_compress_prep(&$contents, $filename, $aggregate_settings) {
  *
  * @param $contents
  *   Javascript string.
- * @return
- *   array with the size before and after.
+ * @param $log_errors
+ *   FALSE to disable logging to watchdog on failure.
  */
-function advagg_js_compress_jsminplus(&$contents) {
+function advagg_js_compress_jsminplus(&$contents, $log_errors = TRUE) {
   $contents_before = $contents;
 
   // Only include jsminplus.inc if the JSMinPlus class doesn't exist.
@@ -123,8 +183,6 @@ function advagg_js_compress_jsminplus(&$contents) {
   }
   ob_start();
   try {
-    // Strip Byte Order Marks (BOM's) from the file, JSMin+ cannot parse these.
-    $contents = str_replace(pack("CCC", 0xef, 0xbb, 0xbf), "", $contents);
     // JSMin+ the contents of the aggregated file.
     $contents = JSMinPlus::minify($contents);
 
@@ -136,7 +194,9 @@ function advagg_js_compress_jsminplus(&$contents) {
   }
   catch (Exception $e) {
     // Log the exception thrown by JSMin+ and roll back to uncompressed content.
-    watchdog('advagg_js_compress', $e->getMessage() . '<pre>' . $contents_before . '</pre>', NULL, WATCHDOG_WARNING);
+    if ($log_errors) {
+      watchdog('advagg_js_compress', $e->getMessage() . '<pre>' . $contents_before . '</pre>', NULL, WATCHDOG_WARNING);
+    }
     $contents = $contents_before;
   }
   ob_end_clean();
@@ -154,18 +214,103 @@ function advagg_js_compress_jspacker(&$contents) {
     include(drupal_get_path('module', 'advagg_js_compress') . '/jspacker.inc');
   }
 
-  // Strip Byte Order Marks (BOM's) from the file, packer cannot parse these.
-  $contents = str_replace(pack("CCC", 0xef, 0xbb, 0xbf), "", $contents);
-
   // Add semicolons to the end of lines if missing.
   $contents = str_replace("}\n", "};\n", $contents);
   $contents = str_replace("\nfunction", ";\nfunction", $contents);
 
-  // Remove char returns,
-  $contents = str_replace("\n\r", "", $contents);
-  $contents = str_replace("\r", "", $contents);
-  $contents = str_replace("\n", "", $contents);
-
   $packer = new JavaScriptPacker($contents, 62, TRUE, FALSE);
   $contents = $packer->pack();
 }
+
+function advagg_js_compress_run_test($filename) {
+  // Get the info on this file.
+  module_load_include('inc', 'advagg', 'advagg');
+  $info = advagg_get_info_on_file($filename);
+  // Cache info.
+  $filename_hashes = &drupal_static('advagg_get_info_on_file');
+  $cache_id = 'advagg:file:' . $info['filename_hash'];
+  $httprl_used = FALSE;
+
+  // Build list of compressors.
+  $compressors = array(0 => 'jsminplus', 2 => 'packer');
+  if (function_exists('jsmin')) {
+    $compressors[1] = 'jsmin';
+    ksort($compressors);
+  }
+
+  // Set to 0 if file doesn't exist.
+  if (empty($info['content_hash'])) {
+    $results = array(
+      0 => array('code' => 0, 'ratio' => 0, 'name' => 'jsminplus'),
+      1 => array('code' => 0, 'ratio' => 0, 'name' => 'jsmin'),
+      2 => array('code' => 0, 'ratio' => 0, 'name' => 'packer'),
+    );
+  }
+  else {
+    // Set to "-1" so if php bombs, the file will be marked as bad.
+    $results = array(
+      0 => array('code' => -1, 'ratio' => 0, 'name' => 'jsminplus'),
+      1 => array('code' => -1, 'ratio' => 0, 'name' => 'jsmin'),
+      2 => array('code' => -1, 'ratio' => 0, 'name' => 'packer'),
+    );
+    // Run this via httprl if possible.
+    if (!module_exists('httprl') || !httprl_is_background_callback_capable()) {
+      // Place results into array.
+      $info['advagg_js_compress'] = $results;
+      // Save results, so if PHP bombs, this file is marked as bad.
+      $filename_hashes[$cache_id] = $info;
+      if (variable_get('advagg_use_file_cache', ADVAGG_USE_FILE_CACHE)) {
+        cache_set($cache_id, $info, 'cache_advagg_info', CACHE_PERMANENT);
+      }
+
+      $results = advagg_js_compress_test_file($filename, $compressors);
+      $httprl_used = FALSE;
+    }
+    else {
+      $httprl_used = TRUE;
+      // Setup callback options array.
+      $callback_options = array(
+        array(
+          'function' => 'advagg_js_compress_test_file',
+          'return' => &$results,
+        ),
+        $filename, $compressors,
+      );
+      // Queue up the request.
+      httprl_queue_background_callback($callback_options);
+      // Execute request.
+      httprl_send_request();
+
+      // If php bombs out, try each compressor indivudially.
+      foreach ($results as $key => $value) {
+        if ($value['code'] == -1) {
+          $sub_result = array();
+          $sub_result[$key] = $value;
+          // Setup callback options array.
+          $callback_options = array(
+            array(
+              'function' => 'advagg_js_compress_test_file',
+              'return' => &$sub_result,
+            ),
+            $filename, array($key => $value['name']),
+          );
+          // Queue up the request.
+          httprl_queue_background_callback($callback_options);
+          // Execute request.
+          httprl_send_request();
+
+          $results[$key] = $sub_result[$key];
+        }
+      }
+    }
+  }
+  // Place results into array.
+  $info['advagg_js_compress'] = $results;
+
+  // Save results.
+  $filename_hashes[$cache_id] = $info;
+  if (variable_get('advagg_use_file_cache', ADVAGG_USE_FILE_CACHE)) {
+    cache_set($cache_id, $info, 'cache_advagg_info', CACHE_PERMANENT);
+  }
+  return $info;
+}
diff --git a/advagg_js_compress/advagg_js_compress.module b/advagg_js_compress/advagg_js_compress.module
index d74d7ed..a1bb476 100644
--- a/advagg_js_compress/advagg_js_compress.module
+++ b/advagg_js_compress/advagg_js_compress.module
@@ -24,7 +24,7 @@ define('ADVAGG_JS_COMPRESS_RATIO', 0.1);
 /**
  * Default value for the compression ratio test.
  */
-define('ADVAGG_JS_MAX_COMPRESS_RATIO', 0.98);
+define('ADVAGG_JS_MAX_COMPRESS_RATIO', 0.90);
 
 /**
  * Default value to see if this will compress aggregated files.
@@ -62,3 +62,53 @@ function advagg_js_compress_advagg_current_hooks_hash_array_alter(&$aggregate_se
   $aggregate_settings['variables']['advagg_js_compress_packer'] = variable_get('advagg_js_compress_packer', ADVAGG_JS_COMPRESS_PACKER);
   $aggregate_settings['variables']['advagg_js_max_compress_ratio'] = variable_get('advagg_js_max_compress_ratio', ADVAGG_JS_MAX_COMPRESS_RATIO);
 }
+
+/**
+ * Test a file, making sure it is compressable.
+ *
+ * @param $filename
+ *   Path and filename of the js file to test.
+ * @param $compressors
+ *   List of compressors to test.
+ * @return
+ *   Array showing the results of the compression tests.
+ */
+function advagg_js_compress_test_file($filename, $compressors) {
+  $contents = file_get_contents($filename);
+  // Get the JS string length before the compression operation.
+  $contents_before = $contents;
+  $before = strlen($contents);
+
+  module_load_include('inc', 'advagg_js_compress', 'advagg_js_compress.advagg');
+
+  $results = array();
+  foreach ($compressors as $key => $name) {
+    $contents = $contents_before;
+    $aggregate_settings['variables']['advagg_js_compressor'] = $key;
+    $aggregate_settings['variables']['advagg_js_max_compress_ratio'] = variable_get('advagg_js_max_compress_ratio', ADVAGG_JS_MAX_COMPRESS_RATIO);
+
+    // Compress it.
+    advagg_js_compress_prep($contents, $filename, $aggregate_settings, FALSE, FALSE, FALSE);
+    $after = strlen($contents);
+
+    $ratio = 0;
+    if ($before != 0) {
+      $ratio = ($before - $after) / $before;
+    }
+    // Set to "-2" if compression ratio sucks (it's already compressed).
+    if ($ratio < variable_get('advagg_js_compress_ratio', ADVAGG_JS_COMPRESS_RATIO)) {
+      $results[$key] = array('code' => -2, 'ratio' => round($ratio, 5), 'name' => $name);
+    }
+    // Set to "-3" if the compression ratio is way too good (bad js output).
+    elseif ($ratio > variable_get('advagg_js_max_compress_ratio', ADVAGG_JS_MAX_COMPRESS_RATIO)) {
+      $results[$key] = array('code' => -3, 'ratio' => round($ratio, 5), 'name' => $name);
+    }
+    // Set to "1". Everything worked, mark this file as compressible.
+    else {
+      $results[$key] = array('code' => 1, 'ratio' => round($ratio, 5), 'name' => $name);
+    }
+  }
+  return $results;
+}
+
+