diff --git a/frappe/core/doctype/file/file.py b/frappe/core/doctype/file/file.py
index 04704d85b7..15cce06c57 100644
--- a/frappe/core/doctype/file/file.py
+++ b/frappe/core/doctype/file/file.py
@@ -9,7 +9,7 @@ naming for same name files: file.gif, file-1.gif, file-2.gif etc
 """
 
 import frappe, frappe.utils
-from frappe.utils.file_manager import delete_file_data_content, get_content_hash
+from frappe.utils.file_manager import delete_file_data_content, get_content_hash, get_random_filename
 from frappe import _
 
 from frappe.utils.nestedset import NestedSet
@@ -172,9 +172,19 @@ class File(NestedSet):
 						raise
 
 				image = Image.open(StringIO.StringIO(r.content))
-				filename, extn = self.file_url.rsplit("/", 1)[1].rsplit(".", 1)
 
-				mimetype = mimetypes.guess_type(filename + "." + extn)[0]
+				try:
+					filename, extn = self.file_url.rsplit("/", 1)[1].rsplit(".", 1)
+				except ValueError:
+					# the case when the file url doesn't have filename or extension
+					# but is fetched due to a query string. example: https://encrypted-tbn3.gstatic.com/images?q=something
+					filename = get_random_filename()
+					extn = ""
+
+				mimetype = None
+				if extn:
+					mimetype = mimetypes.guess_type(filename + "." + extn)[0]
+
 				if mimetype is None or not mimetype.startswith("image/"):
 					# detect file extension by reading image header properties
 					extn = imghdr.what(filename + "." + extn, h=r.content)
diff --git a/frappe/public/js/frappe/upload.js b/frappe/public/js/frappe/upload.js
index 0e65acf7cc..2aa8bef8d1 100644
--- a/frappe/public/js/frappe/upload.js
+++ b/frappe/public/js/frappe/upload.js
@@ -78,6 +78,10 @@ frappe.upload = {
 
 		var dataurl = null;
 		var _upload_file = function() {
+			if (args.file_size) {
+				frappe.upload.validate_max_file_size(args.file_size);
+			}
+
 			if(opts.on_attach) {
 				opts.on_attach(args, dataurl)
 			} else {
@@ -133,12 +137,14 @@ frappe.upload = {
 					frappe.utils.resize_image(freader, function(_dataurl) {
 						dataurl = _dataurl;
 						args.filedata = _dataurl.split(",")[1];
+						args.file_size = Math.round(args.filedata.length * 3 / 4);
 						console.log("resized!")
 						_upload_file();
 					})
 				} else {
 					dataurl = freader.result;
 					args.filedata = freader.result.split(",")[1];
+					args.file_size = fileobj.size;
 					_upload_file();
 				}
 			};
@@ -157,5 +163,15 @@ frappe.upload = {
 
 		return decodeURIComponent(escape(atob(a)));
 
+	},
+
+	validate_max_file_size: function(file_size) {
+		var max_file_size = frappe.boot.max_file_size || 5242880;
+
+		if (file_size > max_file_size) {
+			// validate max file size
+			frappe.throw(__("File size exceeded the maximum allowed size of {0} MB", [max_file_size / 1048576]));
+		}
 	}
 }
+