diff --git a/README.md b/README.md
index 0c8d283..efb526d 100644
--- a/README.md
+++ b/README.md
@@ -184,6 +184,9 @@ You can also have a look at this [example project](https://github.com/Rudloff/al
 We also provide a JSON API that you can use like this:
 [/json?url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DdQw4w9WgXcQ](https://alltubedownload.net/json?url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DdQw4w9WgXcQ)
 
+It returns a JSON object generated by youtube-dl.
+You can find a list of all the properties [in the youtube-dl documentation](https://github.com/rg3/youtube-dl#output-template).
+
 ## FAQ
 
 Please read the [FAQ](resources/FAQ.md) before reporting any issue.