Use lower case and add md2.

index.php

@@ -45,9 +45,10 @@ if(isset($_POST['input']) && isset($_POST['type'])) {
             <br>
 
             <select class="form-control" name="type" id="type">
-                <option value="SHA1">SHA1</option>
-                <option value="SHA256">SHA256</option>
-                <option value="MD5">MD5</option>
+                <option value="sha1">sha1</option>
+                <option value="sha256">sha256</option>
+                <option value="md2">md2</option>
+                <option value="md5">md5</option>
             </select>
 
             <br>