diff --git a/src/kemal/helpers/helpers.cr b/src/kemal/helpers/helpers.cr
index d3ac682..cc32386 100644
--- a/src/kemal/helpers/helpers.cr
+++ b/src/kemal/helpers/helpers.cr
@@ -57,3 +57,19 @@ def send_file(env, path : String, mime_type : String? = nil)
     IO.copy(file, env.response)
   end
 end
+
+# Send a file with given data and default `application/octet-stream` mime_type.
+#
+#   send_file env, data_slice
+#
+# Optionally you can override the mime_type
+#
+#   send_file env, data_slice, "image/jpeg"
+
+def send_file(env, data : Slice(UInt8), mime_type : String? = nil)
+  mime_type ||= "application/octet-stream"
+
+  env.response.content_type = mime_type
+  env.response.content_length = data.bytesize
+  env.response.write data
+end