diff --git a/README.md b/README.md
index 0a2eef1..a939096 100644
--- a/README.md
+++ b/README.md
@@ -16,6 +16,13 @@ Run:
 python crawler.py -u https://urltocrawl.com [-c 100]
 ```
 
+Flags:
+
+  - -u/--url https://url.com
+    - The base URL is required.
+  - -c/--concurrency 100
+    - Specifying concurrency value is optional (defaults to 100).
+
 ## Results
 
 The resulting sitemap will be output to the root of this directory as `sitemap.html`