diff --git a/README.md b/README.md
index e037034..a87cd71 100644
--- a/README.md
+++ b/README.md
@@ -8,6 +8,14 @@ Command line visualizer for the minecraft [NBT](https://wiki.vg/NBT) data file f
 
 Files will have their filetype auto guessed based on their file extension: `.nbt`, `.snbt`, `.json`, unless one is manually specified. The NBT format is the default.
 
+### file types
+
+The current supported file formats are
+
+- `nbt` - Named Binary Tag
+- `snbt` - String Named Binary Tag (TODO!!)
+- `json` - Java Script Object Notation (lossy)
+
 #### complementation
 
 To build and install run