diff --git a/src/_h5ai/client/js/inc/ext/download.js b/src/_h5ai/client/js/inc/ext/download.js
index 5743b0a3..c7ea7713 100644
--- a/src/_h5ai/client/js/inc/ext/download.js
+++ b/src/_h5ai/client/js/inc/ext/download.js
@@ -42,10 +42,14 @@ modulejs.define('ext/download', ['_', '$', 'core/event', 'core/location', 'core/
                 action: 'download',
                 as: name + '.' + extension,
                 type: type,
-                baseHref: location.getAbsHref(),
-                hrefs: _.pluck(selectedItems, 'absHref').join('|:|')
+                baseHref: location.getAbsHref()
             };
 
+        _.each(selectedItems, function (item, idx) {
+
+            query['hrefs[' + idx + ']'] = item.absHref;
+        });
+
         server.formRequest(query);
     }
 
diff --git a/src/_h5ai/client/js/inc/ext/preview-img.js b/src/_h5ai/client/js/inc/ext/preview-img.js
index 3841fab4..a13cbbef 100644
--- a/src/_h5ai/client/js/inc/ext/preview-img.js
+++ b/src/_h5ai/client/js/inc/ext/preview-img.js
@@ -20,14 +20,16 @@ modulejs.define('ext/preview-img', ['_', '$', 'core/event', 'core/server', 'core
         }
 
         server.request({
-            action: 'getThumbHref',
-            type: 'img',
-            href: href,
-            width: settings.size,
-            height: 0
+            action: 'get',
+            thumbs: [{
+                type: 'img',
+                href: href,
+                width: settings.size,
+                height: 0
+            }]
         }, function (json) {
 
-            callback(json && json.href ? json.href : null);
+            callback(json && json.thumbs && json.thumbs[0] ? json.thumbs[0] : null);
         });
     }
 
diff --git a/src/_h5ai/client/js/inc/ext/thumbnails.js b/src/_h5ai/client/js/inc/ext/thumbnails.js
index 6885645a..10d1f561 100644
--- a/src/_h5ai/client/js/inc/ext/thumbnails.js
+++ b/src/_h5ai/client/js/inc/ext/thumbnails.js
@@ -7,21 +7,23 @@ modulejs.define('ext/thumbnails', ['_', 'core/event', 'core/server', 'core/setti
             doc: ['x-pdf', 'x-ps'],
             delay: 1,
             size: 100,
-            exif: true
+            exif: false
         }, allsettings.thumbnails);
 
 
     function requestThumb(type, href, ratio, callback) {
 
         server.request({
-            action: 'getThumbHref',
-            type: type,
-            href: href,
-            width: Math.round(settings.size * ratio),
-            height: settings.size
+            action: 'get',
+            thumbs: [{
+                type: type,
+                href: href,
+                width: Math.round(settings.size * ratio),
+                height: settings.size
+            }]
         }, function (json) {
 
-            callback(json && json.href ? json.href : null);
+            callback(json && json.thumbs && json.thumbs[0] ? json.thumbs[0] : null);
         });
     }
 
diff --git a/src/_h5ai/server/php/inc/class-api.php b/src/_h5ai/server/php/inc/class-api.php
index 0676b676..fc391206 100644
--- a/src/_h5ai/server/php/inc/class-api.php
+++ b/src/_h5ai/server/php/inc/class-api.php
@@ -14,7 +14,7 @@ class Api {
     public function apply() {
 
         $action = Util::get_request_param("action");
-        $supported = array("login", "logout", "get", "getThumbHref", "download");
+        $supported = array("login", "logout", "get", "download");
         Util::json_fail(Util::ERR_UNSUPPORTED, "unsupported action", !in_array($action, $supported));
 
         $methodname = "on_${action}";
@@ -71,28 +71,19 @@ class Api {
             $response["items"] = $this->app->get_items($href, $what);
         }
 
+        if (Util::get_request_param("thumbs", false)) {
+
+            Util::json_fail(Util::ERR_DISABLED, "thumbnails disabled", !$this->app->get_option("thumbnails.enabled", false));
+            Util::json_fail(Util::ERR_UNSUPPORTED, "thumbnails not supported", !HAS_PHP_JPEG);
+
+            $thumbs = Util::get_request_param("thumbs");
+            $response["thumbs"] = $this->app->get_thumbs($thumbs);
+        }
+
         Util::json_exit($response);
     }
 
 
-    private function on_getThumbHref() {
-
-        Util::json_fail(Util::ERR_DISABLED, "thumbnails disabled", !$this->app->get_option("thumbnails.enabled", false));
-        Util::json_fail(Util::ERR_UNSUPPORTED, "thumbnails not supported", !HAS_PHP_JPEG);
-
-        $type = Util::get_request_param("type");
-        $src_href = Util::get_request_param("href");
-        $width = Util::get_request_param("width");
-        $height = Util::get_request_param("height");
-
-        $thumb = new Thumb($this->app);
-        $thumb_href = $thumb->thumb($type, $src_href, $width, $height);
-        Util::json_fail(Util::ERR_FAILED, "thumbnail creation failed", $thumb_href === null);
-
-        Util::json_exit(array("href" => $thumb_href));
-    }
-
-
     private function on_download() {
 
         Util::json_fail(Util::ERR_DISABLED, "downloads disabled", !$this->app->get_option("download.enabled", false));
@@ -104,8 +95,6 @@ class Api {
 
         $archive = new Archive($this->app);
 
-        $hrefs = explode("|:|", trim($hrefs));
-
         set_time_limit(0);
         header("Content-Type: application/octet-stream");
         header("Content-Disposition: attachment; filename=\"$as\"");
diff --git a/src/_h5ai/server/php/inc/class-app.php b/src/_h5ai/server/php/inc/class-app.php
index 92ceeac9..6686f42b 100644
--- a/src/_h5ai/server/php/inc/class-app.php
+++ b/src/_h5ai/server/php/inc/class-app.php
@@ -383,4 +383,24 @@ class App {
             "footerType" => $footer_type
         );
     }
+
+
+    public function get_thumbs($requests) {
+
+        $hrefs = [];
+
+        foreach ($requests as $req) {
+            $type = $req["type"];
+            $src_href = $req["href"];
+            $width = $req["width"];
+            $height = $req["height"];
+
+            $thumb = new Thumb($this);
+            $thumb_href = $thumb->thumb($type, $src_href, $width, $height);
+
+            $hrefs[] = $thumb_href;
+        }
+
+        return $hrefs;
+    }
 }