diff --git a/doc/reference.md b/doc/reference.md
index 8dbe4f293..df2f2cfcb 100644
--- a/doc/reference.md
+++ b/doc/reference.md
@@ -134,6 +134,21 @@ SweetPea ESP-210 | 4M | 3M
 #include "FS.h"
 ```
 
+### Uploading files to file system
+
+*ESP8266FS* is a tool which integrates into the Arduino IDE. It adds a menu item to *Tools* menu for uploading the contents of sketch data directory into ESP8266 flash file system.
+
+- Download the tool: http://arduino.esp8266.com/ESP8266FS-1.6.5-1092-g6c7557b.zip
+- In your Arduino sketchbook directory, create `tools` directory if it doesn't exist yet
+- Unpack the tool into `tools` directory (the path will look like `<home_dir>/Arduino/tools/ESP8266FS/tool/esp8266fs.jar`)
+- Restart Arduino IDE
+- Open a sketch (or create a new one and save it)
+- Go to sketch directory (choose Sketch > Show Sketch Folder)
+- Create a directory named `data` and any files you want in the file system there
+- Make sure you have selected a board, port, and closed Serial Monitor
+- Select Tools > ESP8266 Sketch Data Upload. This should start uploading the files into ESP8266 flash file system. When done, IDE status bar will display `SPIFFS Image Uploaded` message.
+
+
 ### File system object (SPIFFS)
 
 #### begin