diff --git a/4chan_x.user.js b/4chan_x.user.js
index b674ea843..009a804e4 100644
--- a/4chan_x.user.js
+++ b/4chan_x.user.js
@@ -1216,6 +1216,13 @@
     close: function() {
       return qr.el.hidden = true;
     },
+    error: function(err) {
+      $('.error', qr.el).textContent = err;
+      return alert(err);
+    },
+    cleanError: function() {
+      return $('.error', qr.el).textContent = null;
+    },
     quote: function(e) {
       var caretPos, id, s, sel, ta, text, _ref;
       if (e != null) e.preventDefault();
@@ -1233,6 +1240,27 @@
       ta.focus();
       return ta.selectionEnd = ta.selectionStart = caretPos + text.length;
     },
+    fileInput: function() {
+      var file, _i, _len, _ref;
+      qr.cleanError();
+      if (this.files.length === 1) {
+        if (this.files[0].size > this.max) {
+          qr.error('File too large.');
+        } else {
+
+        }
+        return;
+      }
+      _ref = this.files;
+      for (_i = 0, _len = _ref.length; _i < _len; _i++) {
+        file = _ref[_i];
+        if (file.size > this.max) {
+          qr.error("File " + file.name + " is too large.");
+          break;
+        }
+      }
+      return $.addClass(qr.el, 'dump');
+    },
     dialog: function() {
       var file, input, name, _ref;
       qr.el = ui.dialog('qr', 'top:0;right:0;', '\
@@ -1311,7 +1339,7 @@ textarea.field {\
   <div><textarea title=Comment placeholder=Comment class=field></textarea><div>\
   <div class=captcha><img></div>\
   <div><input name=captcha title=Verification placeholder=Verification class=field size=1></div>\
-  <div><input type=file name=upfile><input type=submit value=Submit></div>\
+  <div><input type=file name=upfile multiple><input type=submit value=Submit></div>\
   <div class=error></div>\
 </form>');
       $.on($('#autohide', qr.el), 'click', qr.hide);
@@ -1347,12 +1375,14 @@ textarea.field {\
             return 'image/' + type;
         }
       });
+      file.max = $('[name=MAX_FILE_SIZE]').value;
+      $.on(file, 'change', qr.fileInput);
       return $.add(d.body, qr.el);
     },
     submit: function(e) {
       if (e != null) e.preventDefault();
       if (conf['Auto Hide QR']) qr.hide();
-      return $('.error', qr.el).textContent = null;
+      return qr.cleanError();
     },
     response: function(e) {
       var input, name, _ref, _results;
diff --git a/script.coffee b/script.coffee
index 02e1effc9..566e53374 100644
--- a/script.coffee
+++ b/script.coffee
@@ -877,16 +877,20 @@ qr =
       qr.hide.call input
     else
       qr.dialog()
-
   hide: ->
     if this.checked
       $.addClass qr.el, 'autohide'
     else
       $.removeClass qr.el, 'autohide'
-
   close: ->
     qr.el.hidden = true
 
+  error: (err) ->
+    $('.error', qr.el).textContent = err
+    alert err
+  cleanError: ->
+    $('.error', qr.el).textContent = null
+
   quote: (e) ->
     e?.preventDefault()
     qr.open()
@@ -907,6 +911,22 @@ qr =
     #move the caret to the end of the new quote
     ta.selectionEnd = ta.selectionStart = caretPos + text.length
 
+  fileInput: ->
+    qr.cleanError()
+    if @files.length is 1
+      if @files[0].size > @max
+        qr.error 'File too large.'
+      else
+        # modify selected reply's file
+      return
+    for file in @files
+      if file.size > @max
+        qr.error "File #{file.name} is too large."
+        break
+      # add new reply
+      # set reply's file
+    $.addClass qr.el, 'dump'
+
   dialog: ->
     qr.el = ui.dialog 'qr', 'top:0;right:0;', '
 <style>
@@ -984,7 +1004,7 @@ textarea.field {
   <div><textarea title=Comment placeholder=Comment class=field></textarea><div>
   <div class=captcha><img></div>
   <div><input name=captcha title=Verification placeholder=Verification class=field size=1></div>
-  <div><input type=file name=upfile><input type=submit value=Submit></div>
+  <div><input type=file name=upfile multiple><input type=submit value=Submit></div>
   <div class=error></div>
 </form>'
     $.on $('#autohide', qr.el), 'click',  qr.hide
@@ -1014,13 +1034,15 @@ textarea.field {
           'application/PDF'
         else
           'image/' + type
+    file.max = $('[name=MAX_FILE_SIZE]').value
+    $.on file, 'change', qr.fileInput
 
     $.add d.body, qr.el
 
   submit: (e) ->
     e?.preventDefault()
     qr.hide() if conf['Auto Hide QR']
-    $('.error', qr.el).textContent = null
+    qr.cleanError()
     # magical xhr2
 
   response: (e) ->